"that's original" seems to be a castle communications cd series, cat# TFO *, for * = 1 through at least 21 (though i've not found every cat# along the way); however, it appears to also be a castle communications lp label, cat# TFOLP *, for * = 1 through at least 25 (again, i've not found examples of all), and a cassette series, both overlapping the castle communications cd series most inconsiderately.
45worlds.com maybe should have a warning attached to cd, lp & tape instances of the series/label, advising of this and also saying which it is treated as, in which world. . . ?
(the origin of the cat# prefix seems to've been the fly records, later cube records, "TOOFA *" cat#ed series, reissuing originally single albums in one double, gatefold-sleeved release; but the TFO * cd series, and the TFOLP * label, were/are not constrained to releasing titles from these vinyl labels' back catalogues: almost anyaudiothing to which castle communications've picked up the rights seems to be fair game, if there're two - or more - single albums that can be so packaged.)
I see where you're coming from captain,and i remember vaguely this being discussed quite a while ago,when CD Album World was created.i can't remember the exact outcome to be honest,but i think the consensus was to add any series as tags,which,when tagged,works,i.e,if you search "That's Original",they will all come up (i've just tagged these video games "XBOX LIVE" for example.(I believe the same will happen if the series is added to the notes),personally,i go by what's on the spines when it comes to adding CD's,as a general rule-of-thumb it seems to work,most of the time (there will always be exceptions of course;),but if in doubt about label/title/Cat.No.,the spine is a good place to start,as often,that information is used in the catalogues etc.
Fair enough, my thinking behind it was for the reason that if you typed in "That's Original" in the search bar that you could bring this series up as a group. Would it be possible to introduce another field into CD Albums world so you could do just that. A field maybe called Series Title. At the least if somebody searched the series they might find a disc they wouldn't be aware of otherwise. Just a thought. I also think the composer credits for disc 2 has a typo on the cover and that "AOX" should really be "BOX"