Some time ago I had similar doubts about a plethora of (some) marked
and (some) unmarked "things" on some boards...
https://www.eevblog.com/forum/repair/smd-fuse-or-resistor-marked-as-0-(zero)/msg1928416/#msg1928416The answers are almost uniform in that JUMPERS are still alive and well
in the form of those parts... (e.g. VIAS DID NOT RETIRED JUMPERS...)
Nevertheless I had a closer look in other boards where some UNMARKED parts
were just COLOR CODE BASED. (green yellow blue...)
My attempts to understand SMD codes are still unresolved...
All the SMD references are damn confuse were labels can be anything
from transistor to resistor or just in those cases - nothing. a plain jumper.
Considering that you really find that particular code defined...
On the other hand ... old school parts are very well marked and defined
I have spent a lot of time with that sort of problem...
with a box of "parts" just undefined
or with a label you just can not find anywhere
Paul