Difference between $ and #

[martin.lester]

I've read most of the documentation and I still can't work this out.

What is the difference between {$MACRO} and {#MACRO}?

I've also read somewhere that {$$MACRO} is valid to give dynamic macros, is {##MACRO} also valid?

[batchenr]

I've read most of the documentation and I still can't work this out.

What is the difference between {$MACRO} and {#MACRO}?

I've also read somewhere that {$$MACRO} is valid to give dynamic macros, is {##MACRO} also valid?

if im not worng {#MACRO} used for Regular expressions
for exsample in Template linux os you can find the discovery rule :

Free disk space on {#FSNAME}

and you can find them under - Administration -> General -> and in the scrol down menu ->Regular expressions

the other question i dont know