This tutorial is mainly for admins new or newish to making code alterations with "snippets" - bits of code provided by the more experienced in advice threads here. BUT the same rules apply for more complicated changes too. So don't be too proud to check if there's a useful detail here for you to keep things safe.
Perfect information for the newbie, with insightful TIPS like Always keep a LOG of your individual changes…or else, you will SURELY wish you had! Tips 1 (LOG), 5 (SAFETY) and 10 (LABEL) are VERY beneficial to a non-coder who is experimenting with code snippets.