After preparing the sources, the programmer creates a PO template file.
This section explains how to use
xgettext for this purpose.
xgettext creates a file named domainname.po. You
should then rename it to domainname.pot. (Why doesn't
xgettext create it under the name domainname.pot
right away? The answer is: for historical reasons. When
was specified, the distinction between a PO file and PO file template
was fuzzy, and the suffix ‘.pot’ wasn't in use at that time.)