In addition what is the max length of the "DDE ACRONYM"
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Technically, there is no limit to the ACRONYM length in RDMFieldDictionary.
However, we recommend the max length of 10 characters for ACRONYM and 18 characters for DDE ACRONYM.
Thanks for your answer.Is it a cosmetic recommendation or has it also a technical background?
It is a technical recommendation. If you plan to deploy the dictionary on TREP and non-API product download the dictionary, it may not be able to display the ACRONYM if it over the recommended value.
And please note that unlike RDMFieldDictionary, the legacy appendix_a's ACRONYM does have a limit of 255 characters.