From wikipedia: [The symbol ω is used] in relational database theory to represent NULL, a missing or inapplicable value.
http://en.wikipedia.org/wiki/First_uncountable_ordinal
basically going as far as possible in the sequence C, C++, ...
The wikipedia page I referenced, loosely summarized, is referring to an ordinal number with the cardinality aleph-1. The plain omega that I should have referenced has cardinality aleph-0.
Unfortunately, the ordinal I wanted does not have its own wikipedia page. WTF? Merely countable is not notable enough?
In my font, it's wide enough to be a Unicode ass.