Not always true, many software component use other conversion exit not only ALPHA.
- First check actual conversion exit for domain MATNR.
- Then double-click on exit (ALPHA, MATN1 or other value)
- It will display implementing FM of the FM, there will be the usual CONVERSION_EXIT_XXXXX_INPUT / OUTPUT FM but there can also exist some CONVERSION_EXIT_XXXX_RANGE_I / O
- Next step is : Analyze those FM to understand. (or jump to source code of convert_selopt_expand_convexit(saplsdh4) or similar forms)
Regards,
Raymond