to'a zei lerfu zei-lujvo

x1 (la'e zo BY/word-bu) is a lower-case letter/digit/symbol in alphabet/character-set x2 representing x3.

See also lerfu, to'a, ga'e zei lerfu.

On affix form:

lerfu
x1 (la'e zo BY/word-bu) is a letter/digit/symbol in alphabet/character-set x2 representing x3.
tonga
x1 is a tone/note of frequency/pitch x2 from source x3.
zekri
x1 (event/state) is a punishable crime/[taboo/sin] to people/culture/judges/jury x2.

In definition:

zeiljvo
x1 (text) is a Lojban compound predicate using the particle “zei”; with meaning x2, arguments x3, built from metaphor (tanru) x4.
zejvo
x1 (text) is a Lojban compound predicate using the particle “zei”; with meaning x2, arguments x3, built from metaphor (tanru) x4.
zo si si zei fa'o
x1 is a nonsense zei-lujvo using parts x2, silly by standard x3.

In notes:

ga'e zei lerfu
x1 (la'e zo BY/word-bu) is a capital/capitalised/upper-shift letter/digit/symbol in alphabet/character-set x2 representing x3.
to'alfu
x1 (la'e zo BY/word-bu) is a lower-case letter/digit/symbol in alphabet/character-set x2 representing x3.