Re: 3.2 tables and the width attribute

Domingo Siliceo <638net@medusa.es> wrote:

> On 10 May 96, Murray Altheim wrote:
> >    1. When entered as "attribute value literals", the
> >       attribute is enclosed in either single or double
> >       quotes. [...]
> 
> So, as far as HTML doesn't accept inline macros, could you give me an 
> example of a non-literal value?


The word "literal" is used here in its formal (SGML) sense.
In SGML terminology a literal is a syntactic construct meaning,
basically, "stuff in quotes".  Literals aren't necessarily 
"literal" in the sense that you might be considering, since
they can contain entity references.


There are three kinds of literals in SGML:

  1) Attribute value literals, which appear in attribute
     specifications.  General entity references (&aaa;)
     and character references (&#nnn;) are recognized
     and replaced in attribute value literals (so, e.g.,
     <IMG ALT="&lt;foo&gt;"> does the expected thing.)

  2) Parameter literals, which appear in markup declarations
     (i.e., in the DTD).  In parameter literals, character references 
     (&#nnn;) and _parameter_ entity references (%aaa;) are recognized
     and replaced; general entity references (&aaa;) are not.
     For example, the fourth parameter in: 

<!ENTITY % text "#PCDATA | %font | %phrase | %special | %form">
     
     is a parameter literal.

  3) Minimum literals, which are used in PUBLIC and SYSTEM 
     identifiers.  No markup is recognized in minimum literals.
     For example, in 

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">

    "-//IETF//DTD ...//EN" is a minimum literal.


--Joe English

  joe@art.com

Received on Sunday, 12 May 1996 15:10:26 UTC