bpo-34962: make doctest in Doc now passes, and is enforced in CI by matrixise · Pull Request #9806 · python/cpython

something: :: is equivalent to something::, but the shorter the better.

In reST :: touching a word is introducing a block and displaying :, while :: after a space is only introducing a block, not displaying :. So blah:: and blah: :: are the same. (Hence the usage of : :: in the french translation).