Puñña-kiriya-vatthu: ‘bases of meritorious action’. In the suttas, 3 are mentioned consisting of giving generosity; dāna - maya - p of morality sīla - maya - p and of mental development meditation; bhāvanā - maya - p. See D. 33; It. 60; expl. in A. VIII, 36.
Commentaries have a list of ten dasa p which is very popular in Buddhist countries: 1-3 as above, 4 reverence apaciti 5 service veyyāvacca 6 transference of merit pattānuppadāna 7 rejoicing in others’ merit abbhānumodana 8 expounding the Doctrine desanā 9 listening to the Doctrine savana 10 straightening one’s right views rectification of views; ditthujukamma - Expl. in Atthasālini Tr. 209ff.
See ‘The Advantages of Merit’, by Bhikkhu Khantipalo BODHI LEAVES B. 38.