Ask and you shall receive - http://doc.silverstripe.org/templates#modulus_and_multipleof.

We're trying to be proactive with the docs. A huge effort is taking place to rebuilt and rewrite, tidy up so if you see something missing that should be documented (like this) throw up a ticket to open.silverstripe.org. We will be dealing with those in the coming months.

I personally at least get carried away with new features and code and because I know it, everyone else must know it but I'm attempting to change such bad habits

Modulus and multipleof are great. I'm trying to use them to detect the first and last items in a row of four columns, but...

This works:

<% if MultipleOf(4) %> I'm a multiple of 4 <% end_if %>

This doesn't:

<% if MultipleOf(4, 3) %> Anything as a second parameter breaks <% end_if %>

I cannot see why I cannot pass the second parameter, anyone?

Agree to kcd's issue. Same Problem. Inside a loop

the following works:
(every 3rd Element starting by 1 => 1,4,7,10....)

{$MultipleOf(3,3)}

the following does not:
(results in Parse error: syntax error, unexpected '}' in....)

<% if MultipleOf(3,3) %>

Any ideas would be great ...