Softcode is written in-game and usually to make actions easier for staff and players.
If you type '+help' (no quotes) on XMR, you will see a list of all the available softcode. Most of these commands will have a + sign next to them as part of the command which helps to tell them apart from code already built into (or hardcoded into) the game (WHO, QUIT, page commands, etc. are all hardcoded in).
So, when you type +who, +where, +fcs or even +char for your character sheet, you are making use of softcode which has been created by a coder on-game (likely Paradigm).
Softcode, since it's written on-game (instead of in the back-end of the game code), can often be adjusted and modified by a coder on staff if necessary.