+Note that since each of the @var{macargs} can be an identifier exactly
+as any other one permitted by the target architecture, there may be
+occasional problems if the target hand-crafts special meanings to certain
+characters when they occur in a special position. For example, if colon
+(@code{:}) is generally permitted to be part of a symbol name, but the
+architecture specific code special-cases it when occuring as the final
+character of a symbol (to denote a label), then the macro parameter
+replacement code will have no way of knowing that and consider the whole
+construct (including the colon) an identifier, and check only this
+identifier for being the subject to parameter substitution. In this
+example, besides the potential of just separating identifier and colon
+by white space, using alternate macro syntax (@xref{Altmacro}.) and
+ampersand (@code{&}) as the character to separate literal text from macro
+parameters (or macro parameters from one another) would provide a way to
+achieve the same effect:
+
+@example
+ .altmacro
+ .macro label l
+l&:
+ .endm
+@end example
+
+This applies identically to the identifiers used in @code{.irp} (@xref{Irp}.)
+and @code{.irpc} (@xref{Irpc}.).
+