Some people like to use the vowel that was dropped from the gismu as the last
vowel of the fu'ivla, or repeat the previous vowel of the fu'ivla as the
last.
When lojbanizing a Latin word ending in "-us" or "-um", those being the second
declension ending, the "s" or "m" is dropped. The vowel may be left as "u" or
changed to "o" (which is the corresponding ending in several Romance
languages).