POEdit Keyword Header Value questions

poedit-questions.md

Thanks for looking :-)

I was looking at some typical POEdit keyword header value in WordPress plugins and themes - e.g.:

'__;_e;__ngettext:1,2;_n:1,2;__ngettext_noop:1,2;_n_noop:1,2;_c,_nc:4c,1,2;_x:1,2c;_ex:1,2c;_nx:4c,1,2;_nx_noop:4c,1,2;\n';

There's several things wrong here, but the oddity is:

_c,_nc:4c,1,2

_c( $string ) and _nc( $string, $plural ) are both deprecated anyway, but:

1. They are split by a comma, instead of a semi-colon. Is this allowed, or is that a typo?
2. There's not four arguments, so that 4c, is completely wrong and shouldn't be there?
3. For _nx( $string, $plural, $number, $context ) the keyword value is given as _nx:4c,1,2. Should that be _nx:1,2,4c or does the order not matter?
4. Should this (and all header values in a pot) end with \n for a new line?

Thanks!

1. Typo, presumably. Poedit splits the specifiers with ;, everything within that is xgettext syntax for the keyword argument.
2. Looks like that. See https://www.gnu.org/software/gettext/manual/html_node/xgettext-Invocation.html for the documentation of the syntax.
3. I think the order doesn't matter, but am not sure. See xgettext docs or experiment with it.
4. See PO format docs at http://pology.nedohodnik.net/doc/user/en_US/ch-poformat.html#sec-poheader — the headers have the form of "Name: value\n". Your example seems wrong, the end single quote is wrong (should be double quote); the ; at the end is not needed (but harmless).

Thanks for answering those @vslavik. Good to know that 1. and 2. were definitely wrong, though a lack of understanding means this _c,nc:4c1,2 is present in lots more than just a handful of plugins and themes, as folks have just copied and pasted without understanding (as have I previously).

For 4., I think that's my mistake as I copied the list from PHP which generates the .pot but good to know about the PO format docs.