Syntax for "Ignore section"

I have previously used a syntax that allowed me to ignore an entire section, instead of a single line which can be done using the

 "//" but I have forgotten the syntax and can't find it in the manual. I think it was something like *// (=start ignoring) //* (=end ignoring)

Anyone know this syntax?
I am not sure Igor has it. My routine is to highlight block of text to comment out and use the "Commentize" command in the Edit menu. Likewise "Decommentize" to remove the comment codes from a highlighted block of text.

Igor doesn't have a multi-line comment syntax like many other languages have. However, you can do something like:

[... some code ...]
#if 0
[... code here is disabled ...]
[... some other code ...]

Everything between the #if 0 and the #endif will be ignored.