Column naming conventions for RD views

Columns that correspond to study-specific metadata such as itemset names, control names, and so forth, are created based on the following naming conventions, and must follow the following rules.

Each column name is truncated to 30 characters, including any text that is automatically appended to the column name.
For example, if the RefName for a control with units exceeds 30 characters, the column name for the normalized unit symbol for the control would contain the first 27 characters of the RefName, followed by _NU, resulting in a column name with a total length of 30 characters.
The special characters _-()/",+%@#$&*!~|{}[]<>:;?\ are removed from each study object RefName before it is appended with the appropriate suffix.

Column names must be unique within each view.

If a column name for a control conflicts with the column name for a key variable, the control column name is appended with a number to ensure uniqueness.
For example, if a form contains a date control called DOV, it is renamed DOV2 so as not to conflict with the key variable DOV column.

If a column name for a control conflicts with a column name for another control, each control is assigned a column name that corresponds to the COLUMNNAME value from the CV view for the form on which the control exists. If the COLUMNNAME value in the CV view includes a prefix, the prefix is stripped for the RD view.

Column naming conventions for RD views

Naming convention	Description
Simple and group controls
<controlrefname>	Text or numeric value for the control or entered control data.
<controlrefname>_N	Normalized value for the control data.
<controlrefname>_U	Entered unit symbol for the control.
<controlrefname>_NU	Normalized unit symbol entered for the control.
Radio and pulldown controls
<controlrefname>	Label value for the control.
<controlrefname>_C	Coded value for the control.
Date/time controls
<controlrefname>	Valid complete date/time. If the control is empty, or if a user entered UNK for the control, this column is populated with NULL.
<controlrefname>_DTS	ISO-compliant date/time string in YYYY-MM-DDThh:mm:ss format, where: YYYY—Four-digit year. MM—Two-digit month (01 through 12). DD—Two-digit day (01 through 31). T—Time designator. hh—Two-digit hour, in 24-hour format (01 through 23). mm—Two-digit minute (00 through 59). ss—Two-digit second (00 through 59).
<controlrefname>_DTR	Raw date/time string. This column includes UNK for unknown date/time data, and only appears in the RD view if the date/time control contains fields that are not required, and for which a user can enter UNK.
<controlrefname>_TMS	ISO-compliant time string in Thh:mm:ss format, where: T—Time designator. hh—Two-digit hour, in 24-hour format (01 through 23). mm—Two-digit minute (00 through 59). ss—Two-digit second (00 through 59).
<controlrefname>_TMR	Raw time string. This column includes UNK for unknown time data, and only appears in the RD view if the time control contains fields that are not required, and for which a user can enter UNK.
Checkbox controls
<itemrefname>_<childcontrolrefname>	Label value for the control and child control.
<itemrefname>_<childcontrolrefname>_C	Coded value for the control and child control.
Items
<itemrefname>_ND	Incomplete item reason. For example, Not Done, Not Applicable, Unknown.
Itemsets
<controlrefname>_IB	Control name of the blank item in a Repeating Data itemset.