UDF-spec is actually defined here: https://www.autoitscript.com/wiki/UDF-spec I always want to ask many questions about UDF-spec, in particular in relation to: https://www.autoitscript.com/wiki/Best_coding_practices Now when I submit: My questions came back to my mind, at least in part.   Question 1: The first of what I would like to ask is:   Why the specification says nothing about using: #Region some description..... .... #EndRegion?? I use them more and more, as in the above UDF.