diff --git a/inst/csv/OMOP_CDMv5.3_Field_Level.csv b/inst/csv/OMOP_CDMv5.3_Field_Level.csv
index 7ff7335..bacf480 100644
--- a/inst/csv/OMOP_CDMv5.3_Field_Level.csv
+++ b/inst/csv/OMOP_CDMv5.3_Field_Level.csv
@@ -147,10 +147,10 @@ measurement,measurement_date,Yes,date,Use this date to determine the date of the
 measurement,measurement_datetime,No,datetime,NA,"This is not required, though it is in v6. If a source does not specify datetime the convention is to set the time to midnight (00:00:0000)",No,No,NA,NA,NA,NA,NA
 measurement,measurement_time,No,varchar(10),NA,This is present for backwards compatibility and will be deprecated in an upcoming version.,No,No,NA,NA,NA,NA,NA
 measurement,measurement_type_concept_id,Yes,integer,"This field can be used to determine the provenance of the Measurement record, as in whether the measurement was from an EHR system, insurance claim, registry, or other sources.","Choose the MEASUREMENT_TYPE_CONCEPT_ID that best represents the provenance of the record, for example whether it came from an EHR record or billing claim. [Accepted Concepts](https://athena.ohdsi.org/search-terms/terms?domain=Type+Concept&standardConcept=Standard&page=1&pageSize=15&query=).",No,Yes,CONCEPT,CONCEPT_ID,Type Concept,NA,NA
-measurement,operator_concept_id,No,integer,"The meaning of Concept [4172703](https://athena.ohdsi.org/search-terms/terms/4172703) for '=' is identical to omission of a OPERATOR_CONCEPT_ID value. Since the use of this field is rare, it's important when devising analyses to not to forget testing for the content of this field for values different from =.","Operators are <, <=, =, >=, > and these concepts belong to the 'Meas Value Operator' domain. [Accepted Concepts](https://athena.ohdsi.org/search-terms/terms?domain=Meas+Value+Operator&standardConcept=Standard&page=1&pageSize=15&query=).",No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
+measurement,operator_concept_id,No,integer,"The meaning of Concept [4172703](https://athena.ohdsi.org/search-terms/terms/4172703) for '=' is identical to omission of a OPERATOR_CONCEPT_ID value. Since the use of this field is rare, it's important when devising analyses to not to forget testing for the content of this field for values different from =.","Operators are <, <=, =, >=, > and these concepts belong to the 'Meas Value Operator' domain. [Accepted Concepts](https://athena.ohdsi.org/search-terms/terms?domain=Meas+Value+Operator&standardConcept=Standard&page=1&pageSize=15&query=). Leave it NULL if there's an exact numeric value given (instead of putting '=') or there's no numeric value at all.",No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
 measurement,value_as_number,No,float,"This is the numerical value of the Result of the Measurement, if available. Note that measurements such as blood pressures will be split into their component parts i.e. one record for systolic, one record for diastolic.","If there is a negative value coming from the source, set the VALUE_AS_NUMBER to NULL, with the exception of the following Measurements (listed as LOINC codes):<br>-  [1925-7](https://athena.ohdsi.org/search-terms/terms/3003396) Base excess in Arterial blood by calculation - [1927-3](https://athena.ohdsi.org/search-terms/terms/3002032) Base excess in Venous blood by calculation - [8632-2](https://athena.ohdsi.org/search-terms/terms/3006277) QRS-Axis - [11555-0](https://athena.ohdsi.org/search-terms/terms/3012501) Base excess in Blood by calculation - [1926-5](https://athena.ohdsi.org/search-terms/terms/3003129) Base excess in Capillary blood by calculation - [28638-5](https://athena.ohdsi.org/search-terms/terms/3004959) Base excess in Arterial cord blood by calculation [28639-3](https://athena.ohdsi.org/search-terms/terms/3007435) Base excess in Venous cord blood by calculation",No,No,NA,NA,NA,NA,NA
-measurement,value_as_concept_id,No,integer,If the raw data gives a categorial result for measurements those values are captured and mapped to standard concepts in the 'Meas Value' domain.,"If the raw data provides categorial results as well as continuous results for measurements, it is a valid ETL choice to preserve both values. The continuous value should go in the VALUE_AS_NUMBER field and the categorical value should be mapped to a standard concept in the 'Meas Value' domain and put in the VALUE_AS_CONCEPT_ID field. This is also the destination for the 'Maps to value' relationship.",No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
-measurement,unit_concept_id,No,integer,"There is currently no recommended unit for individual measurements, i.e. it is not mandatory to represent Hemoglobin a1C measurements as a percentage. UNIT_SOURCE_VALUES should be mapped to a Standard Concept in the Unit domain that best represents the unit as given in the source data.","There is no standardization requirement for units associated with MEASUREMENT_CONCEPT_IDs, however, it is the responsibility of the ETL to choose the most plausible unit.",No,Yes,CONCEPT,CONCEPT_ID,Unit,NA,NA
+measurement,value_as_concept_id,No,integer,If the raw data gives a categorial result for measurements those values are captured and mapped to standard concepts in the 'Meas Value' domain.,"If the raw data provides categorial results as well as continuous results for measurements, it is a valid ETL choice to preserve both values. The continuous value should go in the VALUE_AS_NUMBER field and the categorical value should be mapped to a standard concept in the 'Meas Value' domain and put in the VALUE_AS_CONCEPT_ID field. This is also the destination for the 'Maps to value' relationship. If there's no categorial result in a source_data, set value_as_concept_id to NULL, if there is a categorial result in a source_data but without mapping, set value_as_concept_id to 0.",No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
+measurement,unit_concept_id,No,integer,"There is currently no recommended unit for individual measurements, i.e. it is not mandatory to represent Hemoglobin a1C measurements as a percentage. UNIT_SOURCE_VALUES should be mapped to a Standard Concept in the Unit domain that best represents the unit as given in the source data.","There is no standardization requirement for units associated with MEASUREMENT_CONCEPT_IDs, however, it is the responsibility of the ETL to choose the most plausible unit. If the source unit is NULL (applicable to cases when there's no numerical value or when it doesn't require a unit), keep unit_concept_id NULL as well. If there's no mapping of a source unit, populate unit_concept_id with 0.",No,Yes,CONCEPT,CONCEPT_ID,Unit,NA,NA
 measurement,range_low,No,float,Ranges have the same unit as the VALUE_AS_NUMBER. These ranges are provided by the source and should remain NULL if not given.,If reference ranges for upper and lower limit of normal as provided (typically by a laboratory) these are stored in the RANGE_HIGH and RANGE_LOW fields. This should be set to NULL if not provided.,No,No,NA,NA,NA,NA,NA
 measurement,range_high,No,float,Ranges have the same unit as the VALUE_AS_NUMBER. These ranges are provided by the source and should remain NULL if not given.,If reference ranges for upper and lower limit of normal as provided (typically by a laboratory) these are stored in the RANGE_HIGH and RANGE_LOW fields. This should be set to NULL if not provided.,No,No,NA,NA,NA,NA,NA
 measurement,provider_id,No,integer,"The provider associated with measurement record, e.g. the provider who ordered the test or the provider who recorded the result.",The ETL may need to make a choice as to which PROVIDER_ID to put here. Based on what is available this may or may not be different than the provider associated with the overall VISIT_OCCURRENCE record. For example the admitting vs attending physician on an EHR record.,No,Yes,PROVIDER,PROVIDER_ID,NA,NA,NA
@@ -168,9 +168,9 @@ observation,observation_datetime,No,datetime,NA,If no time is given set to midni
 observation,observation_type_concept_id,Yes,integer,"This field can be used to determine the provenance of the Observation record, as in whether the measurement was from an EHR system, insurance claim, registry, or other sources.","Choose the OBSERVATION_TYPE_CONCEPT_ID that best represents the provenance of the record, for example whether it came from an EHR record or billing claim. [Accepted Concepts](https://athena.ohdsi.org/search-terms/terms?domain=Type+Concept&standardConcept=Standard&page=1&pageSize=15&query=).",No,Yes,CONCEPT,CONCEPT_ID,Type Concept,NA,NA
 observation,value_as_number,No,float,"This is the numerical value of the Result of the Observation, if applicable and available. It is not expected that all Observations will have numeric results, rather, this field is here to house values should they exist.",NA,No,No,NA,NA,NA,NA,NA
 observation,value_as_string,No,varchar(60),"This is the categorical value of the Result of the Observation, if applicable and available.",NA,No,No,NA,NA,NA,NA,NA
-observation,value_as_concept_id,No,Integer,"It is possible that some records destined for the Observation table have two clinical ideas represented in one source code. This is common with ICD10 codes that describe a family history of some Condition, for example. In OMOP the Vocabulary breaks these two clinical ideas into two codes; one becomes the OBSERVATION_CONCEPT_ID and the other becomes the VALUE_AS_CONCEPT_ID. It is important when using the Observation table to keep this possibility in mind and to examine the VALUE_AS_CONCEPT_ID field for relevant information.","Note that the value of VALUE_AS_CONCEPT_ID may be provided through mapping from a source Concept which contains the content of the Observation. In those situations, the CONCEPT_RELATIONSHIP table in addition to the 'Maps to' record contains a second record with the relationship_id set to 'Maps to value'. For example, ICD10 [Z82.4](https://athena.ohdsi.org/search-terms/terms/45581076) 'Family history of ischaemic heart disease and other diseases of the circulatory system' has a 'Maps to' relationship to [4167217](https://athena.ohdsi.org/search-terms/terms/4167217) 'Family history of clinical finding' as well as a 'Maps to value' record to [134057](https://athena.ohdsi.org/search-terms/terms/134057) 'Disorder of cardiovascular system'.",No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
+observation,value_as_concept_id,No,Integer,"It is possible that some records destined for the Observation table have two clinical ideas represented in one source code. This is common with ICD10 codes that describe a family history of some Condition, for example. In OMOP the Vocabulary breaks these two clinical ideas into two codes; one becomes the OBSERVATION_CONCEPT_ID and the other becomes the VALUE_AS_CONCEPT_ID. It is important when using the Observation table to keep this possibility in mind and to examine the VALUE_AS_CONCEPT_ID field for relevant information.","Note that the value of VALUE_AS_CONCEPT_ID may be provided through mapping from a source Concept which contains the content of the Observation. In those situations, the CONCEPT_RELATIONSHIP table in addition to the 'Maps to' record contains a second record with the relationship_id set to 'Maps to value'. For example, ICD10 [Z82.4](https://athena.ohdsi.org/search-terms/terms/45581076) 'Family history of ischaemic heart disease and other diseases of the circulatory system' has a 'Maps to' relationship to [4167217](https://athena.ohdsi.org/search-terms/terms/4167217) 'Family history of clinical finding' as well as a 'Maps to value' record to [134057](https://athena.ohdsi.org/search-terms/terms/134057) 'Disorder of cardiovascular system'. If there's no categorial result in a source_data, set value_as_concept_id to NULL, if there is a categorial result in a source_data but without mapping, set value_as_concept_id to 0.",No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
 observation,qualifier_concept_id,No,integer,"This field contains all attributes specifying the clinical fact further, such as as degrees, severities, drug-drug interaction alerts etc.","Use your best judgement as to what Concepts to use here and if they are necessary to accurately represent the clinical record. There is no restriction on the domain of these Concepts, they just need to be Standard.",No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
-observation,unit_concept_id,No,integer,There is currently no recommended unit for individual observation concepts. UNIT_SOURCE_VALUES should be mapped to a Standard Concept in the Unit domain that best represents the unit as given in the source data.,"There is no standardization requirement for units associated with OBSERVATION_CONCEPT_IDs, however, it is the responsibility of the ETL to choose the most plausible unit.",No,Yes,CONCEPT,CONCEPT_ID,Unit,NA,NA
+observation,unit_concept_id,No,integer,There is currently no recommended unit for individual observation concepts. UNIT_SOURCE_VALUES should be mapped to a Standard Concept in the Unit domain that best represents the unit as given in the source data.,"There is no standardization requirement for units associated with OBSERVATION_CONCEPT_IDs, however, it is the responsibility of the ETL to choose the most plausible unit. If the source unit is NULL (applicable to cases when there's no numerical value or when it doesn't require a unit), keep unit_concept_id NULL as well. If there's no mapping of a source unit, populate unit_concept_id with 0.",No,Yes,CONCEPT,CONCEPT_ID,Unit,NA,NA
 observation,provider_id,No,integer,"The provider associated with the observation record, e.g. the provider who ordered the test or the provider who recorded the result.",The ETL may need to make a choice as to which PROVIDER_ID to put here. Based on what is available this may or may not be different than the provider associated with the overall VISIT_OCCURRENCE record. For example the admitting vs attending physician on an EHR record.,No,Yes,PROVIDER,PROVIDER_ID,NA,NA,NA
 observation,visit_occurrence_id,No,integer,The visit during which the Observation occurred.,"Depending on the structure of the source data, this may have to be determined based on dates. If an OBSERVATION_DATE occurs within the start and end date of a Visit it is a valid ETL choice to choose the VISIT_OCCURRENCE_ID from the visit that subsumes it, even if not explicitly stated in the data. While not required, an attempt should be made to locate the VISIT_OCCURRENCE_ID of the observation record. If an observation is related to a visit explicitly in the source data, it is possible that the result date of the Observation falls outside of the bounds of the Visit dates.",No,Yes,VISIT_OCCURRENCE,VISIT_OCCURRENCE_ID,NA,NA,NA
 observation,visit_detail_id,No,integer,"The VISIT_DETAIL record during which the Observation occurred. For example, if the Person was in the ICU at the time the VISIT_OCCURRENCE record would reflect the overall hospital stay and the VISIT_DETAIL record would reflect the ICU stay during the hospital visit.",Same rules apply as for the VISIT_OCCURRENCE_ID.,No,Yes,VISIT_DETAIL,VISIT_DETAIL_ID,NA,NA,NA
@@ -235,7 +235,7 @@ specimen,specimen_type_concept_id,Yes,integer,NA,"Put the source of the specimen
 specimen,specimen_date,Yes,date,The date the specimen was collected.,NA,No,No,NA,NA,NA,NA,NA
 specimen,specimen_datetime,No,datetime,NA,NA,No,No,NA,NA,NA,NA,NA
 specimen,quantity,No,float,The amount of specimen collected from the person.,NA,No,No,NA,NA,NA,NA,NA
-specimen,unit_concept_id,No,integer,The unit for the quantity of the specimen.,Map the UNIT_SOURCE_VALUE to a Standard Concept in the Unit domain. [Accepted Concepts](https://athena.ohdsi.org/search-terms/terms?domain=Unit&standardConcept=Standard&page=1&pageSize=15&query=),No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
+specimen,unit_concept_id,No,integer,The unit for the quantity of the specimen.,"Map the UNIT_SOURCE_VALUE to a Standard Concept in the Unit domain. [Accepted Concepts](https://athena.ohdsi.org/search-terms/terms?domain=Unit&standardConcept=Standard&page=1&pageSize=15&query=). If the source unit is NULL (applicable to cases when there's no numerical value or when it doesn't require a unit), keep unit_concept_id NULL as well. If there's no mapping of a source unit, populate unit_concept_id with 0.",No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
 specimen,anatomic_site_concept_id,No,integer,This is the site on the body where the specimen is from.,Map the ANATOMIC_SITE_SOURCE_VALUE to a Standard Concept in the Spec Anatomic Site domain. This should be coded at the lowest level of granularity [Accepted Concepts](https://athena.ohdsi.org/search-terms/terms?standardConcept=Standard&domain=Spec+Anatomic+Site&conceptClass=Body+Structure&page=4&pageSize=15&query=),No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
 specimen,disease_status_concept_id,No,integer,NA,NA,No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
 specimen,specimen_source_id,No,varchar(50),This is the identifier for the specimen from the source system.,NA,No,No,NA,NA,NA,NA,NA
diff --git a/inst/csv/OMOP_CDMv5.4_Field_Level.csv b/inst/csv/OMOP_CDMv5.4_Field_Level.csv
index 7477eba..783c03c 100644
--- a/inst/csv/OMOP_CDMv5.4_Field_Level.csv
+++ b/inst/csv/OMOP_CDMv5.4_Field_Level.csv
@@ -143,7 +143,7 @@ device_exposure,visit_occurrence_id,No,integer,The Visit during which the device
 device_exposure,visit_detail_id,No,integer,The Visit Detail during which the device was prescribed or given.,To populate this field device exposures must be explicitly initiated in the visit detail record.,No,Yes,VISIT_DETAIL,VISIT_DETAIL_ID,NA,NA,NA
 device_exposure,device_source_value,No,varchar(50),"This field houses the verbatim value from the source data representing the device exposure that occurred. For example, this could be an NDC or Gemscript code.",This code is mapped to a Standard Device Concept in the Standardized Vocabularies and the original code is stored here for reference.,No,No,NA,NA,NA,NA,NA
 device_exposure,device_source_concept_id,No,integer,"This is the concept representing the device source value and may not necessarily be standard. This field is discouraged from use in analysis because it is not required to contain Standard Concepts that are used across the OHDSI community, and should only be used when Standard Concepts do not adequately represent the source detail for the Device necessary for a given analytic use case. Consider using DEVICE_CONCEPT_ID instead to enable standardized analytics that can be consistent across the network.",If the DEVICE_SOURCE_VALUE is coded in the source data using an OMOP supported vocabulary put the concept id representing the source value here.,No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
-device_exposure,unit_concept_id,No,integer,UNIT_SOURCE_VALUES should be mapped to a Standard Concept in the Unit domain that best represents the unit as given in the source data.,"There is no standardization requirement for units associated with DEVICE_CONCEPT_IDs, however, it is the responsibility of the ETL to choose the most plausible unit. If there is no unit associated with a Device record, set to NULL.",No,Yes,CONCEPT,CONCEPT_ID,Unit,NA,NA
+device_exposure,unit_concept_id,No,integer,UNIT_SOURCE_VALUES should be mapped to a Standard Concept in the Unit domain that best represents the unit as given in the source data.,"There is no standardization requirement for units associated with DEVICE_CONCEPT_IDs, however, it is the responsibility of the ETL to choose the most plausible unit. If the source unit is NULL (applicable to cases when there's no numerical value or when it doesn't require a unit), keep unit_concept_id NULL as well. If there's no mapping of a source unit, populate unit_concept_id with 0.",No,Yes,CONCEPT,CONCEPT_ID,Unit,NA,NA
 device_exposure,unit_source_value,No,varchar(50),"This field houses the verbatim value from the source data representing the unit of the Device. For example, blood transfusions are considered devices and can be given in mL quantities.","This code is mapped to a Standard Condition Concept in the Standardized Vocabularies and the original code is stored here for reference. Using the blood transfusion example, blood transfusion is represented by the DEVICE_CONCEPT_ID and the unit (mL) would be housed in the UNIT_SOURCE_VALUE and mapped to a standard concept in the unit domain.",No,No,NA,NA,NA,NA,NA
 device_exposure,unit_source_concept_id,No,integer,"This is the concept representing the UNIT_SOURCE_VALUE and may not necessarily be standard. This field is discouraged from use in analysis because it is not required to contain Standard Concepts that are used across the OHDSI community, and should only be used when Standard Concepts do not adequately represent the source detail for the Unit necessary for a given analytic use case. Consider using UNIT_CONCEPT_ID instead to enable standardized analytics that can be consistent across the network.",If the UNIT_SOURCE_VALUE is coded in the source data using an OMOP supported vocabulary put the concept id representing the source value here.,No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
 measurement,measurement_id,Yes,integer,The unique key given to a Measurement record for a Person. Refer to the ETL for how duplicate Measurements during the same Visit were handled.,"Each instance of a measurement present in the source data should be assigned this unique key. In some cases, a person can have multiple records of the same measurement within the same visit. It is valid to keep these duplicates and assign them individual, unique, MEASUREMENT_IDs, though it is up to the ETL how they should be handled.",Yes,No,NA,NA,NA,NA,NA
@@ -153,10 +153,10 @@ measurement,measurement_date,Yes,date,Use this date to determine the date of the
 measurement,measurement_datetime,No,datetime,NA,"This is not required, though it is in v6. If a source does not specify datetime the convention is to set the time to midnight (00:00:0000)",No,No,NA,NA,NA,NA,NA
 measurement,measurement_time,No,varchar(10),NA,This is present for backwards compatibility and will be deprecated in an upcoming version.,No,No,NA,NA,NA,NA,NA
 measurement,measurement_type_concept_id,Yes,integer,"This field can be used to determine the provenance of the Measurement record, as in whether the measurement was from an EHR system, insurance claim, registry, or other sources.","Choose the MEASUREMENT_TYPE_CONCEPT_ID that best represents the provenance of the record, for example whether it came from an EHR record or billing claim. [Accepted Concepts](https://athena.ohdsi.org/search-terms/terms?domain=Type+Concept&standardConcept=Standard&page=1&pageSize=15&query=). A more detailed explanation of each Type Concept can be found on the [vocabulary wiki](https://github.com/OHDSI/Vocabulary-v5.0/wiki/Vocab.-TYPE_CONCEPT).",No,Yes,CONCEPT,CONCEPT_ID,Type Concept,NA,NA
-measurement,operator_concept_id,No,integer,"The meaning of Concept [4172703](https://athena.ohdsi.org/search-terms/terms/4172703) for '=' is identical to omission of a OPERATOR_CONCEPT_ID value. Since the use of this field is rare, it's important when devising analyses to not to forget testing for the content of this field for values different from =.","Operators are <, <=, =, >=, > and these concepts belong to the 'Meas Value Operator' domain. [Accepted Concepts](https://athena.ohdsi.org/search-terms/terms?domain=Meas+Value+Operator&standardConcept=Standard&page=1&pageSize=15&query=).",No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
+measurement,operator_concept_id,No,integer,"The meaning of Concept [4172703](https://athena.ohdsi.org/search-terms/terms/4172703) for '=' is identical to omission of a OPERATOR_CONCEPT_ID value. Since the use of this field is rare, it's important when devising analyses to not to forget testing for the content of this field for values different from =.","Operators are <, <=, =, >=, > and these concepts belong to the 'Meas Value Operator' domain. [Accepted Concepts](https://athena.ohdsi.org/search-terms/terms?domain=Meas+Value+Operator&standardConcept=Standard&page=1&pageSize=15&query=). Leave it NULL if there's an exact numeric value given (instead of putting '=') or there's no numeric value at all.",No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
 measurement,value_as_number,No,float,"This is the numerical value of the Result of the Measurement, if available. Note that measurements such as blood pressures will be split into their component parts i.e. one record for systolic, one record for diastolic.","If there is a negative value coming from the source, set the VALUE_AS_NUMBER to NULL, with the exception of the following Measurements (listed as LOINC codes):<br>-  [1925-7](https://athena.ohdsi.org/search-terms/terms/3003396) Base excess in Arterial blood by calculation - [1927-3](https://athena.ohdsi.org/search-terms/terms/3002032) Base excess in Venous blood by calculation - [8632-2](https://athena.ohdsi.org/search-terms/terms/3006277) QRS-Axis - [11555-0](https://athena.ohdsi.org/search-terms/terms/3012501) Base excess in Blood by calculation - [1926-5](https://athena.ohdsi.org/search-terms/terms/3003129) Base excess in Capillary blood by calculation - [28638-5](https://athena.ohdsi.org/search-terms/terms/3004959) Base excess in Arterial cord blood by calculation [28639-3](https://athena.ohdsi.org/search-terms/terms/3007435) Base excess in Venous cord blood by calculation",No,No,NA,NA,NA,NA,NA
-measurement,value_as_concept_id,No,integer,If the raw data gives a categorial result for measurements those values are captured and mapped to standard concepts in the 'Meas Value' domain.,"If the raw data provides categorial results as well as continuous results for measurements, it is a valid ETL choice to preserve both values. The continuous value should go in the VALUE_AS_NUMBER field and the categorical value should be mapped to a standard concept in the 'Meas Value' domain and put in the VALUE_AS_CONCEPT_ID field. This is also the destination for the 'Maps to value' relationship.",No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
-measurement,unit_concept_id,No,integer,"There is currently no recommended unit for individual measurements, i.e. it is not mandatory to represent Hemoglobin a1C measurements as a percentage. UNIT_SOURCE_VALUES should be mapped to a Standard Concept in the Unit domain that best represents the unit as given in the source data.","There is no standardization requirement for units associated with MEASUREMENT_CONCEPT_IDs, however, it is the responsibility of the ETL to choose the most plausible unit.",No,Yes,CONCEPT,CONCEPT_ID,Unit,NA,NA
+measurement,value_as_concept_id,No,integer,If the raw data gives a categorial result for measurements those values are captured and mapped to standard concepts in the 'Meas Value' domain.,"If the raw data provides categorial results as well as continuous results for measurements, it is a valid ETL choice to preserve both values. The continuous value should go in the VALUE_AS_NUMBER field and the categorical value should be mapped to a standard concept in the 'Meas Value' domain and put in the VALUE_AS_CONCEPT_ID field. This is also the destination for the 'Maps to value' relationship. If there's no categorial result in a source_data, set value_as_concept_id to NULL, if there is a categorial result in a source_data but without mapping, set value_as_concept_id to 0.",No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
+measurement,unit_concept_id,No,integer,"There is currently no recommended unit for individual measurements, i.e. it is not mandatory to represent Hemoglobin a1C measurements as a percentage. UNIT_SOURCE_VALUES should be mapped to a Standard Concept in the Unit domain that best represents the unit as given in the source data.","There is no standardization requirement for units associated with MEASUREMENT_CONCEPT_IDs, however, it is the responsibility of the ETL to choose the most plausible unit. If the source unit is NULL (applicable to cases when there's no numerical value or when it doesn't require a unit), keep unit_concept_id NULL as well. If there's no mapping of a source unit, populate unit_concept_id with 0.",No,Yes,CONCEPT,CONCEPT_ID,Unit,NA,NA
 measurement,range_low,No,float,Ranges have the same unit as the VALUE_AS_NUMBER. These ranges are provided by the source and should remain NULL if not given.,If reference ranges for upper and lower limit of normal as provided (typically by a laboratory) these are stored in the RANGE_HIGH and RANGE_LOW fields. This should be set to NULL if not provided.,No,No,NA,NA,NA,NA,NA
 measurement,range_high,No,float,Ranges have the same unit as the VALUE_AS_NUMBER. These ranges are provided by the source and should remain NULL if not given.,If reference ranges for upper and lower limit of normal as provided (typically by a laboratory) these are stored in the RANGE_HIGH and RANGE_LOW fields. This should be set to NULL if not provided.,No,No,NA,NA,NA,NA,NA
 measurement,provider_id,No,integer,"The provider associated with measurement record, e.g. the provider who ordered the test or the provider who recorded the result.",The ETL may need to make a choice as to which PROVIDER_ID to put here. Based on what is available this may or may not be different than the provider associated with the overall VISIT_OCCURRENCE record. For example the admitting vs attending physician on an EHR record.,No,Yes,PROVIDER,PROVIDER_ID,NA,NA,NA
@@ -177,9 +177,9 @@ observation,observation_datetime,No,datetime,NA,If no time is given set to midni
 observation,observation_type_concept_id,Yes,integer,"This field can be used to determine the provenance of the Observation record, as in whether the measurement was from an EHR system, insurance claim, registry, or other sources.","Choose the OBSERVATION_TYPE_CONCEPT_ID that best represents the provenance of the record, for example whether it came from an EHR record or billing claim. [Accepted Concepts](https://athena.ohdsi.org/search-terms/terms?domain=Type+Concept&standardConcept=Standard&page=1&pageSize=15&query=). A more detailed explanation of each Type Concept can be found on the [vocabulary wiki](https://github.com/OHDSI/Vocabulary-v5.0/wiki/Vocab.-TYPE_CONCEPT).",No,Yes,CONCEPT,CONCEPT_ID,Type Concept,NA,NA
 observation,value_as_number,No,float,"This is the numerical value of the Result of the Observation, if applicable and available. It is not expected that all Observations will have numeric results, rather, this field is here to house values should they exist.",NA,No,No,NA,NA,NA,NA,NA
 observation,value_as_string,No,varchar(60),"This is the categorical value of the Result of the Observation, if applicable and available.",NA,No,No,NA,NA,NA,NA,NA
-observation,value_as_concept_id,No,Integer,"It is possible that some records destined for the Observation table have two clinical ideas represented in one source code. This is common with ICD10 codes that describe a family history of some Condition, for example. In OMOP the Vocabulary breaks these two clinical ideas into two codes; one becomes the OBSERVATION_CONCEPT_ID and the other becomes the VALUE_AS_CONCEPT_ID. It is important when using the Observation table to keep this possibility in mind and to examine the VALUE_AS_CONCEPT_ID field for relevant information.","Note that the value of VALUE_AS_CONCEPT_ID may be provided through mapping from a source Concept which contains the content of the Observation. In those situations, the CONCEPT_RELATIONSHIP table in addition to the 'Maps to' record contains a second record with the relationship_id set to 'Maps to value'. For example, ICD10 [Z82.4](https://athena.ohdsi.org/search-terms/terms/45581076) 'Family history of ischaemic heart disease and other diseases of the circulatory system' has a 'Maps to' relationship to [4167217](https://athena.ohdsi.org/search-terms/terms/4167217) 'Family history of clinical finding' as well as a 'Maps to value' record to [134057](https://athena.ohdsi.org/search-terms/terms/134057) 'Disorder of cardiovascular system'.",No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
+observation,value_as_concept_id,No,Integer,"It is possible that some records destined for the Observation table have two clinical ideas represented in one source code. This is common with ICD10 codes that describe a family history of some Condition, for example. In OMOP the Vocabulary breaks these two clinical ideas into two codes; one becomes the OBSERVATION_CONCEPT_ID and the other becomes the VALUE_AS_CONCEPT_ID. It is important when using the Observation table to keep this possibility in mind and to examine the VALUE_AS_CONCEPT_ID field for relevant information.","Note that the value of VALUE_AS_CONCEPT_ID may be provided through mapping from a source Concept which contains the content of the Observation. In those situations, the CONCEPT_RELATIONSHIP table in addition to the 'Maps to' record contains a second record with the relationship_id set to 'Maps to value'. For example, ICD10 [Z82.4](https://athena.ohdsi.org/search-terms/terms/45581076) 'Family history of ischaemic heart disease and other diseases of the circulatory system' has a 'Maps to' relationship to [4167217](https://athena.ohdsi.org/search-terms/terms/4167217) 'Family history of clinical finding' as well as a 'Maps to value' record to [134057](https://athena.ohdsi.org/search-terms/terms/134057) 'Disorder of cardiovascular system'. If there's no categorial result in a source_data, set value_as_concept_id to NULL, if there is a categorial result in a source_data but without mapping, set value_as_concept_id to 0.",No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
 observation,qualifier_concept_id,No,integer,"This field contains all attributes specifying the clinical fact further, such as as degrees, severities, drug-drug interaction alerts etc.","Use your best judgement as to what Concepts to use here and if they are necessary to accurately represent the clinical record. There is no restriction on the domain of these Concepts, they just need to be Standard.",No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
-observation,unit_concept_id,No,integer,There is currently no recommended unit for individual observation concepts. UNIT_SOURCE_VALUES should be mapped to a Standard Concept in the Unit domain that best represents the unit as given in the source data.,"There is no standardization requirement for units associated with OBSERVATION_CONCEPT_IDs, however, it is the responsibility of the ETL to choose the most plausible unit.",No,Yes,CONCEPT,CONCEPT_ID,Unit,NA,NA
+observation,unit_concept_id,No,integer,There is currently no recommended unit for individual observation concepts. UNIT_SOURCE_VALUES should be mapped to a Standard Concept in the Unit domain that best represents the unit as given in the source data.,"There is no standardization requirement for units associated with OBSERVATION_CONCEPT_IDs, however, it is the responsibility of the ETL to choose the most plausible unit. If the source unit is NULL (applicable to cases when there's no numerical value or when it doesn't require a unit), keep unit_concept_id NULL as well. If there's no mapping of a source unit, populate unit_concept_id with 0.",No,Yes,CONCEPT,CONCEPT_ID,Unit,NA,NA
 observation,provider_id,No,integer,"The provider associated with the observation record, e.g. the provider who ordered the test or the provider who recorded the result.",The ETL may need to make a choice as to which PROVIDER_ID to put here. Based on what is available this may or may not be different than the provider associated with the overall VISIT_OCCURRENCE record. For example the admitting vs attending physician on an EHR record.,No,Yes,PROVIDER,PROVIDER_ID,NA,NA,NA
 observation,visit_occurrence_id,No,integer,The visit during which the Observation occurred.,"Depending on the structure of the source data, this may have to be determined based on dates. If an OBSERVATION_DATE occurs within the start and end date of a Visit it is a valid ETL choice to choose the VISIT_OCCURRENCE_ID from the visit that subsumes it, even if not explicitly stated in the data. While not required, an attempt should be made to locate the VISIT_OCCURRENCE_ID of the observation record. If an observation is related to a visit explicitly in the source data, it is possible that the result date of the Observation falls outside of the bounds of the Visit dates.",No,Yes,VISIT_OCCURRENCE,VISIT_OCCURRENCE_ID,NA,NA,NA
 observation,visit_detail_id,No,integer,"The VISIT_DETAIL record during which the Observation occurred. For example, if the Person was in the ICU at the time the VISIT_OCCURRENCE record would reflect the overall hospital stay and the VISIT_DETAIL record would reflect the ICU stay during the hospital visit.",Same rules apply as for the VISIT_OCCURRENCE_ID.,No,Yes,VISIT_DETAIL,VISIT_DETAIL_ID,NA,NA,NA
@@ -249,7 +249,7 @@ specimen,specimen_type_concept_id,Yes,integer,NA,"Put the source of the specimen
 specimen,specimen_date,Yes,date,The date the specimen was collected.,NA,No,No,NA,NA,NA,NA,NA
 specimen,specimen_datetime,No,datetime,NA,NA,No,No,NA,NA,NA,NA,NA
 specimen,quantity,No,float,The amount of specimen collected from the person.,NA,No,No,NA,NA,NA,NA,NA
-specimen,unit_concept_id,No,integer,The unit for the quantity of the specimen.,Map the UNIT_SOURCE_VALUE to a Standard Concept in the Unit domain. [Accepted Concepts](https://athena.ohdsi.org/search-terms/terms?domain=Unit&standardConcept=Standard&page=1&pageSize=15&query=),No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
+specimen,unit_concept_id,No,integer,The unit for the quantity of the specimen.,"Map the UNIT_SOURCE_VALUE to a Standard Concept in the Unit domain. [Accepted Concepts](https://athena.ohdsi.org/search-terms/terms?domain=Unit&standardConcept=Standard&page=1&pageSize=15&query=). If the source unit is NULL (applicable to cases when there's no numerical value or when it doesn't require a unit), keep unit_concept_id NULL as well. If there's no mapping of a source unit, populate unit_concept_id with 0.",No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
 specimen,anatomic_site_concept_id,No,integer,This is the site on the body where the specimen is from.,Map the ANATOMIC_SITE_SOURCE_VALUE to a Standard Concept in the Spec Anatomic Site domain. This should be coded at the lowest level of granularity [Accepted Concepts](https://athena.ohdsi.org/search-terms/terms?standardConcept=Standard&domain=Spec+Anatomic+Site&conceptClass=Body+Structure&page=4&pageSize=15&query=),No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
 specimen,disease_status_concept_id,No,integer,NA,NA,No,Yes,CONCEPT,CONCEPT_ID,NA,NA,NA
 specimen,specimen_source_id,No,varchar(50),This is the identifier for the specimen from the source system.,NA,No,No,NA,NA,NA,NA,NA
diff --git a/inst/csv/OMOP_CDMv5.4_Table_Level.csv b/inst/csv/OMOP_CDMv5.4_Table_Level.csv
index 064f18e..89c51a4 100644
--- a/inst/csv/OMOP_CDMv5.4_Table_Level.csv
+++ b/inst/csv/OMOP_CDMv5.4_Table_Level.csv
@@ -77,5 +77,5 @@ concept_ancestor,VOCAB,No,NA,No,NA,NA,"The CONCEPT_ANCESTOR table is designed to
 This table is entirely derived from the CONCEPT, CONCEPT_RELATIONSHIP and RELATIONSHIP tables.",NA,NA
 source_to_concept_map,VOCAB,No,NA,No,NA,NA,"The source to concept map table is recommended for use in ETL processes to maintain local source codes which are not available as Concepts in the Standardized Vocabularies, and to establish mappings for each source code into a Standard Concept as target_concept_ids that can be used to populate the Common Data Model tables. The SOURCE_TO_CONCEPT_MAP table is no longer populated with content within the Standardized Vocabularies published to the OMOP community. **There are OHDSI tools to help you populate this table; [Usagi](https://github.com/OHDSI/Usagi) and [Perseus](https://github.com/ohdsi/Perseus). You can read more about OMOP vocabulary mapping in [The Book of OHDSI Chapter 6.3](https://ohdsi.github.io/TheBookOfOhdsi/ExtractTransformLoad.html#step-2-create-the-code-mappings).**",NA,NA
 drug_strength,VOCAB,No,NA,No,NA,NA,The DRUG_STRENGTH table contains structured content about the amount or concentration and associated units of a specific ingredient contained within a particular drug product. This table is supplemental information to support standardized analysis of drug utilization.,NA,NA
-cohort,RESULTS,No,NA,No,NA,NA,The COHORT table contains records of subjects that satisfy a given set of criteria for a duration of time. The definition of the cohort is contained within the COHORT_DEFINITION table. It is listed as part of the RESULTS schema because it is a table that users of the database as well as tools such as ATLAS need to be able to write to. The CDM and Vocabulary tables are all read-only so it is suggested that the COHORT and COHORT_DEFINTION tables are kept in a separate schema to alleviate confusion.,NA,"Cohorts typically include patients diagnosed with a specific condition, patients exposed to a particular drug, but can also be Providers who have performed a specific Procedure. Cohort records must have a Start Date and an End Date, but the End Date may be set to Start Date or could have an applied censor date using the Observation Period Start Date. Cohort records must contain a Subject Id, which can refer to the Person, Provider, Visit record or Care Site though they are most often Person Ids. The Cohort Definition will define the type of subject through the subject concept id. A subject can belong (or not belong) to a cohort at any moment in time. A subject can only have one record in the cohort table for any moment of time, i.e. it is not possible for a person to contain multiple records indicating cohort membership that are overlapping in time"
+cohort,RESULTS,No,NA,No,NA,NA,"The subject of a cohort can have multiple, discrete records in the cohort table per cohort_definition_id, subject_id, and non-overlapping time periods. The definition of the cohort is contained within the COHORT_DEFINITION table. It is listed as part of the RESULTS schema because it is a table that users of the database as well as tools such as ATLAS need to be able to write to. The CDM and Vocabulary tables are all read-only so it is suggested that the COHORT and COHORT_DEFINTION tables are kept in a separate schema to alleviate confusion.",NA,"Cohorts typically include patients diagnosed with a specific condition, patients exposed to a particular drug, but can also be Providers who have performed a specific Procedure. Cohort records must have a Start Date and an End Date, but the End Date may be set to Start Date or could have an applied censor date using the Observation Period Start Date. Cohort records must contain a Subject Id, which can refer to the Person, Provider, Visit record or Care Site though they are most often Person Ids. The Cohort Definition will define the type of subject through the subject concept id. A subject can belong (or not belong) to a cohort at any moment in time. A subject can only have one record in the cohort table for any moment of time, i.e. it is not possible for a person to contain multiple records indicating cohort membership that are overlapping in time"
 cohort_definition,RESULTS,No,NA,No,NA,NA,"The COHORT_DEFINITION table contains records defining a Cohort derived from the data through the associated description and syntax and upon instantiation (execution of the algorithm) placed into the COHORT table. Cohorts are a set of subjects that satisfy a given combination of inclusion criteria for a duration of time. The COHORT_DEFINITION table provides a standardized structure for maintaining the rules governing the inclusion of a subject into a cohort, and can store operational programming code to instantiate the cohort within the OMOP Common Data Model.",NA,NA
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