How to get string ids for translation?

Hello,

if I understand the documentation correctly, I can’t just enter the labels of test strings for the “settings.xml” file directly into this file. Seems like I have to use some “translation system”. And as far as I see I have to use the “.po” based system.

But how should I set the “IDs” for strings? Are the IDs global or can I use whatever I like as the IDs are only relevant to my own Addon?

If they are global: How can I get my range reserved for my use? I don’t want to use some external translation tool. Just some .po files on Github.