Note: this has not been touched in ages and some comments may consequently be outdated.

El Goonish Shive URL Schemes

Streams

In addition to the main story, there are two subcomics:

Dates and IDs

Archival IDs are used for the current system.  While recent IDs are in order, in the archives IDs can jump foreward and backward either in blocks or individually, and this happens significantly with all the streams, especially filler and newspaper (although the main story is the least badly hit, it is nonetheless hit very significantly).  Likewise, the filler with ID 1 is Brave Sir Rhoda.

In addition to archival IDs, there are also multiple other types of ID for specific ranges, appearing in specific ranges.  Unofficially, each strip up to a certain date (which is not current) also has an ID for the Ookii API (although this not displayed to the user, the API is handled entirely by JavaScript).  In this document, unless specified otherwise, ID refers to an archival ID.

Dates can often be extracted from the filenames, although there are some fillers which do not provide them as well as some strips (in the current Squirrel Prophet storyline) where, while the three-digit c ID and the ten-digit ID (and the displayed date and lookup ID) increment correctly, the filename date is given as the same as the previous strip’s filename date, and this can go on for several days of strips with the same filename date before a correct date is seen.

Filename titles (typically humourous, and typically not the same as captioned titles) were given for some strips in the past, and have gone missing in the move from Keenspot (but are still recorded in the Ookii database).  As of Squirrel Prophet, filename titles are now being assigned to new strips.

Keenspot Date Lookup

This was kept for a short period of time as a redirect to the contemperary PHP date lookup, it no longer functions.

http://www.egscomics.com/d/YYYYMMDD.html
e.g. http://www.egscomics.com/d/20020505.html

http://www.egscomics.com/Filler/d/YYYYMMDD.html
e.g. http://www.egscomics.com/Filler/d/20020701.html

http://www.egscomics.com/egsnp/d/YYYYMMDD.html
e.g. http://www.egscomics.com/egsnp/d/20040224.html

Keenspot Direct Image Lookup

Sometimes seen, no longer functional.  I think it is the following:

e.g. http://www.egscomics.com/egsnp/comics/2004/03/20040321_ZyxK.png

Needless to say, you need the four-character ID and (if applicable) the filename-title (and the image format) to convert to this scheme.  Not that you would do such a conversion, because it no longer functions.

Erm... but egs20060526_thespellcheckingforthiscomicwasachore.gif

Old PHP Date Lookup

Currently seems to redirect to the New PHP Date Lookup.

New PHP Date Lookup

This still works for older strips, but the date displayed in the page <title> is wrong.  It does not function for the latest ones - the last story strip this functions for is the one with ID 1699, the last sketchbook strip it functions for is the one with ID 749

Current ID Lookup

Valid alternative forms of the above schemes

Conclusion

Barring direct-image links (which are bad), a main story strip with year 2002, month 05, day 05 and archival ID 105 might be linked to by any of the following likely links (and several other unlikely ones):

Likewise, a newspaper strip with year 2004, month 03, day 30 and archival ID 27 might plausibly be linked to by any of the following:

Finally, a filler strip with year 2002, month 07, day 14 and archival ID 83 might plausibly be linked to by any of the following:

I would like to say that later strips, of course, have fewer plausible links than earlier ones.  Then again, the Haylo database seems to use the New PHP Date Lookup for strips where this doesn’t actually function ... whatever ...