diff --git a/inst/csv/OMOP_CDMv5.3.1_Field_Level.csv b/inst/csv/OMOP_CDMv5.3.1_Field_Level.csv
index da10426..e278fc7 100644
--- a/inst/csv/OMOP_CDMv5.3.1_Field_Level.csv
+++ b/inst/csv/OMOP_CDMv5.3.1_Field_Level.csv
@@ -407,7 +407,7 @@ VOCABULARY,vocabulary_name,Yes,varchar(255),"The name describing the vocabulary,
 example, International Classification of
 Diseases, Ninth Revision, Clinical
 Modification, Volume 1 and 2 (NCHS) etc.",,No,No,,,,,
-VOCABULARY,vocabulary_reference,Yes,varchar(255),"External reference to documentation or
+VOCABULARY,vocabulary_reference,No,varchar(255),"External reference to documentation or
 available download of the about the
 vocabulary.",,No,No,,,,,
 VOCABULARY,vocabulary_version,No,varchar(255),"Version of the Vocabulary as indicated in
@@ -512,4 +512,4 @@ ATTRIBUTE_DEFINITION,attribute_definition_id,Yes,integer,,,No,No,,,,,
 ATTRIBUTE_DEFINITION,attribute_name,Yes,varchar(255),,,No,No,,,,,
 ATTRIBUTE_DEFINITION,attribute_description,No,varchar(MAX),,,No,No,,,,,
 ATTRIBUTE_DEFINITION,attribute_type_concept_id,Yes,integer,,,No,Yes,CONCEPT,CONCEPT_ID,,,
-ATTRIBUTE_DEFINITION,attribute_syntax,No,varchar(MAX),,,No,No,,,,,
\ No newline at end of file
+ATTRIBUTE_DEFINITION,attribute_syntax,No,varchar(MAX),,,No,No,,,,,
diff --git a/inst/csv/OMOP_CDMv5.4_Field_Level.csv b/inst/csv/OMOP_CDMv5.4_Field_Level.csv
index 866c707..0a75e02 100644
--- a/inst/csv/OMOP_CDMv5.4_Field_Level.csv
+++ b/inst/csv/OMOP_CDMv5.4_Field_Level.csv
@@ -419,7 +419,7 @@ VOCABULARY,vocabulary_name,Yes,varchar(255),"The name describing the vocabulary,
 example, International Classification of
 Diseases, Ninth Revision, Clinical
 Modification, Volume 1 and 2 (NCHS) etc.",,No,No,,,,,
-VOCABULARY,vocabulary_reference,Yes,varchar(255),"External reference to documentation or
+VOCABULARY,vocabulary_reference,No,varchar(255),"External reference to documentation or
 available download of the about the
 vocabulary.",,No,No,,,,,
 VOCABULARY,vocabulary_version,No,varchar(255),"Version of the Vocabulary as indicated in
diff --git a/inst/csv/OMOP_CDMv6.0_Field_Level.csv b/inst/csv/OMOP_CDMv6.0_Field_Level.csv
index c3d2d1e..426d5b3 100644
--- a/inst/csv/OMOP_CDMv6.0_Field_Level.csv
+++ b/inst/csv/OMOP_CDMv6.0_Field_Level.csv
@@ -449,7 +449,7 @@ VOCABULARY,vocabulary_name,Yes,varchar(255),"The name describing the vocabulary,
 example International Classification of
 Diseases, Ninth Revision, Clinical
 Modification, Volume 1 and 2 (NCHS) etc.",,No,No,,,,,
-VOCABULARY,vocabulary_reference,Yes,varchar(255),"External reference to documentation or
+VOCABULARY,vocabulary_reference,No,varchar(255),"External reference to documentation or
 available download of the about the
 vocabulary.",,No,No,,,,,
 VOCABULARY,vocabulary_version,No,varchar(255),"Version of the Vocabulary as indicated in
@@ -544,4 +544,4 @@ COHORT_DEFINITION,cohort_definition_description,No,varchar(MAX),A complete descr
 COHORT_DEFINITION,definition_type_concept_id,Yes,integer,Type defining what kind of Cohort Definition the record represents and how the syntax may be executed.,,No,Yes,CONCEPT,CONCEPT_ID,,,
 COHORT_DEFINITION,cohort_definition_syntax,No,varchar(MAX),Syntax or code to operationalize the Cohort Definition.,,No,No,,,,,
 COHORT_DEFINITION,subject_concept_id,Yes,integer,"This field contains a Concept that represents the domain of the subjects that are members of the cohort (e.g., Person, Provider, Visit).",,No,Yes,CONCEPT,CONCEPT_ID,,,
-COHORT_DEFINITION,cohort_initiation_date,No,date,A date to indicate when the Cohort was initiated in the COHORT table.,,No,No,,,,,
\ No newline at end of file
+COHORT_DEFINITION,cohort_initiation_date,No,date,A date to indicate when the Cohort was initiated in the COHORT table.,,No,No,,,,,