I have seen j for current density only so far. But physics are convinced you can tell the difference by context (which is usually true, but probably impossible

I have seen j for current density only so far. But physics are convinced you can tell the difference by context (which is usually true, but probably impossible for a compiler, even if physics is "typed" with units). For handwritten text at least my professors managed to come up with at least two different ways to write each letter to avoid confusion. My (not serious) attempts to use Chinese characters haven't been very successful.