Descript.ion File Specification
Googling for the "official specification" of the classic descript.ion format, I found only instances on the wayback machine. To make sure this spec doesn't get lost, I'm repeating it here.
JP Software Inc.
P.O. Box 328
Chestertown, MD 21620, USA
410-810-8818
fax 410-810-0026
Email sales@jpsoft.com
Web http://www.jpsoft.com/
Technical Note -- Using DESCRIPT.ION
------------------------------------
4NT and Take Command use the file DESCRIPT.ION to store file descriptions.
This file is created as a hidden file in each subdirectory which has
descriptions, and deleted when all descriptions are removed or when all
files with descriptions are deleted. If you remove the hidden attribute
from the file, it will not be hidden again.
Your programs can access DESCRIPT.ION to create, retrieve, or modify
file descriptions, and to store other information. DESCRIPT.ION has one
line per file, and is unsorted. Each line is in the following format:
filename.ext Description[*Other program info]...
There is normally one space between the description and filename but
additional spaces may be used in future versions. The characters
after the description allow extension of the description format
for use by other programs. They are as follows:
* is an ASCII Ctrl-D (04), and marks the end of the description
text and the beginning of information for a program other than
4NT or Take Command. This symbol can appear multiple times on each
line; each occurrence marks the beginning of information for another
program.
is an identification byte for the program which is using this
area of the particular line. If you are writing a program which
will store information in DESCRIPT.ION, test it using an ID byte of
your own choosing. When you are ready to release the program,
contact JP Software and we will provide you with an ID byte value
that is not in use by others to the best of our knowledge.
Other program info is any text the program wishes to store in its
area of the line. The text should relate specifically to the file
named on the line. It may not contain the Ctrl-D character,
carriage returns, line feeds, or nulls (ASCII 0s).
4NT and Take Command will copy, delete, or move all the information on a
line in DESCRIPT.ION, including information owned by other programs, when
performing the same action on the corresponding file. They will also
change the name if a file is renamed. To support DESCRIPT.ION properly,
your program must do the same if it copies, deletes, moves, or renames
files. Take care not to remove information which does not belong to
your program, or delete lines which contain information for other
programs. Your program should be able to handle a line terminated by a
CR or LF alone, a CR/LF pair, an EOF (ASCII 26), or the physical end of
the file. The lines it creates should be terminated with CR / LF. The
line length limit is 4096 bytes; exceeding this limit will cause
unpredictable results.
=======================================================================
JP Software Inc. P.O. Box 328, Chestertown, MD 21620, USA
phone: 410-810-8818 fax: 410-810-0026
WWW: http://jpsoft.com email: sales@jpsoft.com
From Wikipedia: Known IDs include `0x10` for general metadata in XMP format, `0x23` ('#') as used by various utilities written by Matthias R. Paul for space-separated lists of text key=value pairs holding file properties as extended attributes like CP (codepages), PC (language codes), CW (bit-width), XS (page width), YS (page length), XO (print x-offset), YO (print y-offset), CR (copyright), URL (source link), etc., `0x25` ('%') being used by programs using CUI_LIB to store pseudo-environment variables, `0xED` being reserved for Digital Research/Novell/Caldera, `0xC2` used by Total Commander for multiline file descriptions, and `0xFD` reserved for FreeDOS.
JPSoft still has an internet presence, but I can't find a specification on their site. Documentation for the TCC "Describe" command does mention the format.