0 1em Helvetica 18pt bold 0.5em 1em Helvetica 16pt bold 0.5em 1em Helvetica 14pt bold 0.5em 1em Helvetica 12pt bold 0.5em 1em Helvetica 10pt bold 0.5em 1em Helvetica 10pt bold 0.5em 1em bold 0.5em 0.5em 2em 2em Courier Courier Courier no-wrap start false preserve italic italic bold italic bold Abstract , , ? " " Editor s : - Second Edition (See .) [ ] Table of Contents Appendi ces x < > Constraint: Example: (Non-Normative) Validity constraint: Well-formedness constraint: Copyright  ©    W3C ® ( MIT , INRIA , Keio ), All Rights Reserved. W3C liability , trademark , document use , and software licensing rules apply. Issue ( ): loweralpha lowerroman upperalpha upperroman arabic arabic 1 a i A I Unexpected numeration: • Latest version: ? Note: NOTICE: Previous version s : ( ) This version: This document is also available in these non-normative formats: , and  . " " Resolution: ( )        ::=       ::=    /* */ /* */ /* */ [Constraint: ] [Constraint: ] Source : [ Issue : ] [VC: ] [PROD: ] [ ] Unsupported specref to [ ] (Contact stylesheet maintainer). ??? Missing specref target [specref failure, no ID ' '] Status of this Document This document is an editors' copy that has no official standing. 100% [ Definition : ] [VC: ] [VC: ] [WFC: ] [WFC: ] [ ] --