ca65 documentation of .define macros, making note that parentheses in ca65 macros are problematic especially when thinking of them as "C style", replacing unclear example with an example showing how accidental parentheses can cause a problem.

doc/ca65.sgml

@@ -4282,6 +4282,12 @@ different:
 	some things may be done with both macro types, each type has special
 	usages. The types complement each other.
 
+<item>	Parentheses work differently from C macros.
+	The common practice of wrapping C macros in parentheses may cause
+	unintended problems here, such as accidentally implying an
+	indirect addressing mode. While the definition of a macro requires
+	parentheses around its argument list, when invoked they should not be included.
+
 </itemize>
 
 Let's look at a few examples to make the advantages and disadvantages
@@ -4314,20 +4320,18 @@ Macros with parameters may also be useful:
         DEBUG   "Assembling include file #3"
 </verb></tscreen>
 
-Note that, while formal parameters have to be placed in braces, this is
-not true for the actual parameters. Beware: Since the assembler cannot
-detect the end of one parameter, only the first token is used. If you
-don't like that, use classic macros instead:
+Note that, while formal parameters have to be placed in braces,
+the actual parameters used when invoking the macro should not use braces.
+The invoked parameters are separated by commas only, if parentheses are
+used by accident they will become part of the replaced token:
 
 <tscreen><verb>
-.macro  DEBUG   message
-        .out    message
-.endmacro
+.define COMBINE(ta,tb,tc) ta+tb*10+tc*100
+
+        COMBINE 5,6,7     ; 5+6*10+7*100 = 765 correct
+        COMBINE(5,6,7)    ; (5+6*10+7)*100 = 7200 incorrect!
 </verb></tscreen>
 
-(That is an example where a problem can be solved with both macro types).
-
-
 <sect1>Characters in macros<p>
 
 When using the <ref id="option-t" name="-t"> option, characters are translated