diff -r 39d78c530cbb -r 3ba6a2d26507 plcopen/Makefile
--- a/plcopen/Makefile	Tue Sep 24 11:55:59 2019 +0200
+++ b/plcopen/Makefile	Fri Aug 09 12:07:33 2019 +0200
@@ -1,13 +1,23 @@
 #! gmake
 
-yml := ../../yml2
+# Makefile to generate XSLT stylesheets from ysl2 files in the same directory
+
+# This uses YML2. 
+#   hg clone https://pep.foundation/dev/repos/yml2/
+
+# It should be just fine if yml2 is cloned just asside beremiz
+# otherwise, point yml2path to yml2 source directory
+#   make yml2path=path/to/yml/dir
+
+yml2path ?= $(abspath ../../yml2)
+
 ysl2files := $(wildcard *.ysl2)
 xsltfiles := $(patsubst %.ysl2, %.xslt, $(ysl2files))
 
 all:$(xsltfiles)
 
-%.xslt: %.ysl2 yslt_noindent.yml2
-	$(yml)/yml2c -I $(yml) $< -o $@.tmp
+%.xslt: %.ysl2 ../yslt_noindent.yml2
+	$(yml2path)/yml2c -I $(yml2path):../ $< -o $@.tmp
 	xmlstarlet fo $@.tmp > $@
 	rm $@.tmp