There was a question in the forum last year about texting in Welsh and what abbreviations can be used. A friend has told me that the following book has a section on this subject (I don’t get have a boot myself):
AmrywIAITH 4: Blas ar dafodieithoedd Cymru, gan Guto Rhys (Llyfrau Lafar Gwlad, Gwasg Carreg Gwalch, 2024).
Examples in the book include:
AAB: Allan am beint
DdYS: Ddo i yn syth
DYG: Dweud y gwir
LlTM: Lle ti’n mynd
(I have a screenshot of the page of abbreviations, but couldn’t find a way to post a copy of it here).
Hope this helps. TTTT (ta-ta tan toc) 