Other than hyphen is it only letters and numbers only for the type code?
If some extended graphics symbol then is it date code or makers code or
something other than type designation.?

Faced with 4 symbols SO23 top code of 1F*1 , in a line no spaces, where * is
like the ASCII 172 , NOT symbol , but inverted so the barb points up.
From the schematic this is a BC847B which agrees with the 1F part in a
general SMD code table.
Looking at about 100 of the SMD code pages no reference to symbols other
than hyphen