Dear list, I have the following sample: \startbuffer[demo] <a href="#myspecialid">the previous section</a> \stopbuffer \startxmlsetups xml:initialize \xmlsetsetup{#1}{a}{xml:*} \stopxmlsetups \xmlregistersetup{xml:initialize} \startxmlsetups xml:a \ctxlua{context("\\xmlatt{#1}{href}")} \ctxlua{local originalid = "abcde";% doesn’t work with # tex.print(string.sub(originalid,2))} \stopxmlsetups \starttext \xmlprocessbuffer{main}{demo}{} \stoptext In both for some reason unknown to me, compilation crashes whe string.sub has an string with # inside. How could I get the following command working? \ctxlua{tex.print(string.sub(context("\\xmlatt{#1}{href}"),2))} Even if I remove # from the href attribute, compilation crashes. Sorry for asking this again, but which is the right way to do this? I have spent hours trying to find out how to do it, but I’m afraid this is beyond my knowledge. Many thanks for your help, Pablo -- http://www.ousia.tk