Identifiers return specific values eg. $time would return the current time. Whenever mIRC finds an identifier in a command or script, it replaces it with the current value of that identifier. Many identifiers also perform functions on data that you supply and then return a result.
Identifiers which cannot be evaluated or evaluate to no value return the value $null. The $null value can be used in comparisons in if-then-else statements to control branching etc. You can also place identifiers or variables inside the brackets of other identifiers and they will be evaluated.
The identifiers are organized by groups as follows:
There are also specialized identifiers for Agents, Dde Control, Custom Windows, Picture Windows, Sockets, Remote Scripts, Dialogs, Binary Files, Hash Tables, Regular Expressions, COM Objects, Signals, Multi-server, Internal Address List, Sounds, Toolbar, and File Handling.