Posted by dxli on Jun 14, 2015; 3:52am
URL: https://forum.librecad.org/updating-rs-commands-tp5711646p5711659.html

for the QObject::tr() function is descripted here:

https://wiki.qt.io/QtInternationalization#What_is_tr.28.29.3F

basically, tr("string", "description") means the string would be the translation of the "string", and "description" services a hint useful for people doing the translation, so people can know better what the "string" actually means.