Using/reading/writing the null and escape characters

I know that a filename in Linux has no restriction whatsoever except for two characters '/' and '\0'. I know that '/' is prohibited because it is a directory separator but **is there any other reason** ? Also on my terminal I can create a file or a directory with the name \0. So I wonder **how to write the null character correctly** because obviously it shouldn't allow me to have a filename with null in it mkdir '\0' will create a directory named \0 One more question, If I want to include $ in my filename, I can use the backslash mkdir \$myfile will create a directory named $myfile However, I can do the same if I surround the dollar sign with single quotes and double quotes mkdir \$myfile is the same as mkdir '$'myfile is the same as mkdir "$"myfile is the same as mkdir '$myfile' is the same as mkdir "$myfile" So my question is, **Are the single and double quotes a substitution for the escape backslash character?** **Also what other characters need escaping in bash besides $, (space) and backslash ?**