Is it possible to use more than just lowercase in a username?

Question

Electronics

For example: Sergey . Will this cause problems?

Answer 1

simple quote from wikipedia:
In simple words, this is the same dimension, just not very lucky with the letter. That's why Greek characters are sometimes evil :)

Answer 2

If the letter is the same as in the picture, then these are microfarads. If it is mF, then this is millifarads, 1000 times more (but this is unlikely).
You can supply 2200 uF 16V, it will probably work. 1500 uF 6.3V is not suitable for voltage.

Answer 3

It is possible if SSZB. A table of possible POSIX characters that cannot be used - as the first character of a username.