"Creator, identifier, date, content, and potentially other data" may sound familiar to many:
$ ls -l blog/1472.entry -rw-rw-r-- 1 kilroy kilroy 2114 Jun 21 20:35 1472.entry
Here we have an owner or creator, 'kilroy', date 'Jun 21 20:35', partial URI 'blog/1472.entry', and content. If you're like Apple, BeOS, others, and creative users of filesystems, much more metadata is available. If you have a CMS or weblog tool, the storage is similar in concept.
Multiple, related content is handled much the same:
$ ls -l blog/1486.entry/ total 24 -rw-rw-r-- 1 kilroy kilroy 1728 Jun 22 09:06 1486.entry -rw-rw-r-- 1 kilroy kilroy 16998 Jun 16 13:08 kitty.jpg -rw-rw-r-- 1 kilroy kilroy 112 Jun 22 09:06 1486.meta
What makes a WellFormedEntry, in isolation, unique from any other resource on the web? If you were writing an uber-weblog tool that could take any information item in your possession or available on the web[1,2], and arrange them in chronological order with your authentic voice, is it a "well formed log entry" that does that, or is it the unique collection and presentation of resources that form the essential characteristics of a online Journal or weblog?
See WhatIsAnEntry.