Check that the problem has not already been reported.

Visit the TT-AvXML discussion groupand look for items with [AvXML-1.0] at the start of the subject line. You may find that your problem has already been reported - if it has not been resolved in the thread, you might want to add further information by replying to the post.

If the problem has not already been resolved

Either use the "post" button at the TT-AvXML discussion group
or send an email with a subject line that starts [AvXML-1.0] to cbs-tt-avxml @ wmo.int.

Please include a detailed description of the problem (you may want to include examples or snippets of XML).