Where are built-in identifiers declared?

To find out in which unit an identifier is declared, put the cursor on that identifier and press function key F1. An identifier means: the name of a procedure, function, variable, constant, class,...

But why would you want to know that? Because if the declaring unit isn't known to Delphi's compiler, it stops with an "Undeclared identifier" error, and you have to add the declaring unit to a uses clause of your unit.

Alas, in some cases Delphi's Help files don't show you where a certain identifier is declared. This depends on: your version/edition of Delphi, whether an identifier is considered to be "built-in" (notably, the default Help tells you little or nothing about WinApi functions), and so on... For example, where is the very popular ShellExecute declared? Good luck if you try to find out using Delphi's Help...

Here's a list of Win32 API (Application Program Interface) routines that are available in all Delphi versions from D4 up to D2006 and the units where they are declared:

 Related articles

Jump to declaration
Quickly find the code where a given identifier is declared.
ref-identifier-declarations