Long text attributes

[Markus Kuhn <[e-mail]>]

Several people have already given good reasons, why there 
shouldn't be complete documents stored in the directory (up 
to several MB!).

But I still miss another very important attribute type in the 
Internet schema and in X.520: Explaining textes, that have 
several lines (e.g. 5-100).

The description attribute doesn't seem to be suitable for this.
X.520 tells nothing about line breaks in this attribute and the
PARADISE DUAs don't render it properly, if the text is too long.

We need an attribute, where we can put short descriptions
(a few lines or paragraphs) about an object. This might be
the description of a person, organisation, distrib. list, ...
A single line is too short in most cases.

There are two ways to represent this new attribute syntax:

  a) the text contains explicit CR LF sequences, i.e. the author
     of the text defines the rendering, which is necessary, if the
     text contains some kind of ASCII diagramms. Disadvantage: 
     It is necessary to define a maximum line length. The 
     following criterias should be examined before defining a 
     maximum line length:

      - most terminals can't display more than 80 characters/line
      - typographical rules tell us that a text is most readable 
        with a line length between 50 and 70 characters/line.
      - it is easier for DUAs to make a nice screen layout if
        full 80 charcter lines won't appear.

     => A maximum line length of about 65 characters/line is a
        good choice in my eyes.

     [BTW: No line of this text is longer than 65 chars/line]

  b) a CR LF sequence could also only be interpreted as a NEW 
     PARAGRAPH marker. Each paragraph would then be stored as a
     single long line and the DUA would be responsible for
     breaking it up into several lines. Disadvantage: The
     author has not control about the text layout. Advantage:
     the DUA has full control (and responsibility) for
     presenting the text in the right way.

I personally prefer approach a), because I want to have
full control about the presentation of the text. Just think
about the nice layouts that people have desinged in their
mail/news signatures.

Another requirement for this new attribute/attribute syntax:

The language in which the text is written should be indicated
by a 2 character ISO 639 code (e.g. en=English, de=German,
fr=French, eo=Esperanto, ...) in the attribute.
Then people may store the text in several languages in
the directory and I could tell my DUA to display me

     - only the German text if it exists
     - only the English text, if no German one is
       available
     - only the French text if no English or German version
       is available
     - no text at all if no German/English/French text is
       available, because my Russian and Spanish is quite 
       poor. :-)

A good DUA might also be configurable to not displaying
the description or info attributes if a detailedDescription
attribute (do you like this name?) in the right language is
available.

What to you think about the idea?

Improvements?

Are there DUA authors that would like to support a similar
attribute in the next release?


I also want to propose two other attributes:

  preferedLanguages    -  Which languages do you understand in
                          which order? In which language do you
                          want to be contacted by MHS? Again
                          of course ISO 639 coded.

  geographicalPosition -  ISO 6709: Standard representation of
                          latitude, longitude and altitude for
                          geographic point locations.
                          Useful for drawing maps of networks
                          and for cruise missile flaming. :-)

Tschuess, au revoir, good bye, do svidanja, ...

Markus
(dreaming of a multilingual directory)

-- 
Markus Kuhn, Computer Science student -=-=- University of Erlangen, Germany
Internet: [e-mail]  |  X.500 entry available
Nichts ist gerechter verteilt als der Verstand. Jeder meint genug zu haben.