In {{IMSMANG}} database the rule is unique name per data type '''and''' item. In version 5.x it was not possible to specify name when creating Custom Defined Fields (CDFs). It was only possible to specify the label which then also was set as name. Therefore there are CDFs with names like ''If the answer is No on question 14.1 then fill in the Comment field Medical and Physio'' or ''Specify''.
In version 6.0 it is possible to set the CDF's name '''and''' the name must be according to PostgreSQL rules. The name should be no longer than 60 characters and should only contain ''a - z '' and ''0 - 9'', see full rules on [[Add Custom Defined Fields]]. '''But''' CDFs created with version 5.x do not follow these rules so they may be up 250 characters long and contain any character (\ ? é ô . space). They may also be written with another alphabet e.g. Arabic.
In {{IMSMANG}} the CDF name is contents of a database column but in the Staging area database it will be used a as column name which of cause must be according to PostgreSQL rules. The Staging Area Generator handles CDF names that do not follow the rules:
* any name longer than '''63''' characters will be cut off
* any not supported character will be replaced with underscore including trailing spaces
* to facilitate working with the Staging area or using it with other applications the column name will be in '''lower''' case.
The geo geospatial part of the Staging area is creating SQL views that will be used by GIS software and here the maximum length for column names is '''31''' characters. The Staging Area Generator handles automatically duplicates by renaming them which sometimes is resulting in confusing column names.
[[Image:Staging area geo error.png|500px|center]]
<div align="center">
'' Geospatial part creating creation error caused by duplicate CDF names according to SAG Geo geospatial rules''
</div>
There are cases where the Staging Area Generator cannot handle the duplicates.
| dangerous_area_user_defined_field_1
| dangerous_area_user_defined_f5
| Depending on data it could be confusing that CDF#1 is #5 in the geo geospatial part
|-
| Dangerous Area User Defined Field 2