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 apaciti5 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.
Maha Thera Nyanatiloka. Manual of Buddhist Terms and Doctrines, Buddhist Publication Society, first edition 1952.