In AcuBench, when editing a DLT file, on the XFD tab the name given in the "File Directive:" field is limited to maximum 18 characters.

Although it seems to have no further impact when creating the XFD, the XFD takes on the name of the DLT itself, and not the one specified in the field.

Moreover, when working with a WHEN condition and giving the "Table Name:" option, then the same limitation stands. 

Full article: https://portal.microfocus.com/s/article/KM000013681