Okay to change the DIST_TUPLE example line from '=' to '+='? This way
the porter can combine multiple DIST_TUPLE+= lines for submodules, and
it also works if it's only one line. I hope this small adjustment will
prevent unintentional errors and frustrations when people try it for
its intended purpose...

ok?

Index: Makefile.template
===================================================================
RCS file: /cvs/ports/infrastructure/templates/Makefile.template,v
retrieving revision 1.100
diff -u -p -r1.100 Makefile.template
--- Makefile.template	14 Nov 2023 09:22:09 -0000	1.100
+++ Makefile.template	16 Jan 2024 02:36:12 -0000
@@ -52,7 +52,7 @@ DISTNAME =	???
 #   For a commit hash, use the full hash (not shortened), and set PKGNAME.
 # subdir: usually ".", otherwise the extracted files are moved to another
 #   directory under WRKDIST. Mostly useful for git submodules.
-#DIST_TUPLE =	platform account project id subdir
+#DIST_TUPLE +=	platform account project id subdir
 
 # for any port that creates shared libraries.
 # both libtool and cmake automatically set filenames based on this variable.