<script type="text/javascript"> google_ad_client = "pub-8800625213955058"; /* 336x280, 创建于 07-11-21 */ google_ad_slot = "0989131976"; google_ad_width = 336; google_ad_height = 280; // </script> <script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"> </script> There are numerous projects to convert common or popular SGML DTDs to XML format (for example the TEI DTD, both Lite and full versions). The following checklist comes courtesy of Seán McGrath (author of XML By Example, Prentice Hall, 1998): No equivalent of the SGML Declaration. So keywords, character set etc are essentially fixed; Tag mimimization is not allowed, so
becomes
and
becomes
; #PCDATA must only occur at the extreme left (ie first) in an OR model, eg
(in SGML) becomes
, and
is illegal; No CDATA, RCDATA elements [declared content]; Some SGML attribute types are not allowed in XML eg NUTOKEN; Some SGML attribute defaults are not allowed in XML eg CONREF; Comments cannot be inline to declarations like
]>