BUR #5848 has been approved by @evazion.
Synonyms. Most of the examples under spit appear to be what others would tag saliva. A significant chunk also qualify for saliva_trail on top (which also implies saliva).
There's a handful (<5) of more specific examples that might be better described as spitting or sneezing (and might not necessarily count as saliva), though those can be gardened out. So far only found post #471522 to be problematic (the others all involve visible saliva).
Updated