The modern figurative sense is conforming to the usual standards or rules. This phrase is the survivor of a set of phrases that were common in the nineteenth century. Many early examples are from the British Navy, which is where it may have originated. The image was that of men lining up with the tips of their toes touching some line. They might be on parade, or preparing to undertake some task, or in readiness for a race or fight. The earliest recorded form is dated 1813.

Übersetzung:

sich einordnen

Gegenteil(e)

The opposite of "toe the line" is "to be different".

Synonym(e):

You could also say: confirming to the rules or toe the mark.