This term atta,pa.tilaabha seems to be used only once in the Pali Canon,
that is, at D 1:195,21, where the Buddha tells Po.t.t.hapaada that there
are 3 kinds of "acquired selves", namely, gross-acquired self, mind-made
self, and formless-acquired self. The Commentary glosses this as self
acqured in the sense-world, the form-world and the formless world,
respectively.
[The other occurrence of the term seems to be only in Daa.thu,va.msa 5:64,
according to the CPD (Critical {ali Dictionary).]
Bhikkhu Bodhi, in "The Long Discourses of the Buddha (D translation) is
helpful by giving a note of this term (note 220).
Has Peter (Masefield) or any one else anything to add to this for our
edification.