BibTeX oddity

Comments don't always work in BibTeX files!  I had the following in my bib file:

@STRING{lncs = {LNCS}}
% @STRING{lncs = {Lecture Notes in Computer Science}}

I wanted the shorter "LNCS" rather than "Lecture Notes in Computer Science".  For some reason, the long form kept showing up in my bibliography.  Transposing the lines gives the desired effect.  Weird...