PO files use the file format of the Gettext tools.
Language header (since gettext version 0.17)
Plural forms and plural form handling
msgctxt "noun" msgid "View" msgstr ""
# this is another comment
#. comment extracted from the source code
Source location comments
Msgidcomments, also known as KDE style comments as they are used by KDE for message disambiguation and comments to translators.
Support for this is being phased out in favor of
msgid "_: comment\n" "translation"
#~ msgid "Blah" #~ msgstr "Bleeh"
#| msgid "previous message"
#| msgctxt "previous context"