The short version is the letters A-Z and a-z when preceeded by ! are compiler variables.

Uppercase letters are incremented before use, and lowercase values are just read.

!0 through !9 are replacements for the Paramters in a command.

If you need to embed "!" in a string followed by a letter or a number, break it up so the "!" is in a string on it's own, or is the last character in the string.

so Move ("IUHBiuygJHB!" + "Ahb") to sPassword

or Move (Sformat("IUHBiuygJHB%1Ahb","!")) to sPassword