Composer does not recognise or allow !DOCTYPE tags when composing web pages for eg <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> could not be pasted in, when entered into the html page with a text editor, composer ignored this line and attempted to save a copy of the html file without it
the doctype is automatically inserted in the document, but is not editable by the user. 1. new documents are always given a 4.01 transitional doctype. 2. existing documents that do not contain a doctype and are modified within COmposer are not given a doctype 3. exisiting documents with a doctype type, do not get the doctype altered.
verified in 3/5 build.