Notes for translators are comments for translators - i.e. written by source code author. "Extracted comments" is the official gettext name for this. Comments are comments by translators; notes to self. Consequently, only the latter is editable and it makes no sense to "get it parsed".
Rationale for them can be found in this unofficial, but much better than GNU's, documentation of the file format:
http://pology.nedohodnik.net/doc/user/en_US/ch-poformat.html#sec-pomancmnt http://pology.nedohodnik.net/doc/user/en_US/ch-poformat.html#sec-poautocmnt