I wonder why "1008681031<TAB>7/96 1SB4" is seen as engraved and not etched. For me, this is about the same and I would put them in the same field.
I just found weird to not put "1008681031<TAB>7/96 1SB4" in the mastering code (laser branded/etched) field.
I assume it was probably discussed before I joined, btw.
Some discs have the "1008681031"-like part laser-written, like your Bootleg Sampler and the "7/96 1SB4"-like part goes as a toolstamp. Also, on European and US discs there are common toolstamps like "A1" written with the same font. It's not correct to put the symbols written the same way into the "laser-branded" section for one disc and into the "engraved" section for another. Also, it's quite clear the laser-written mastering IFPI comes from the matrix and gets added when the disc itself is being pressed, while that "1SB4" part is written afterwards, similar to the vinyl ringcodes. You can even scratch such a toolstamp with your needle and feel the the groove.
IFPI L223 is laser branded (clearly visible like other type of code -P1K V), but 610-6055P-00400<TAB>1M1<TAB>C<TAB>57 could be seen as engraved and not laser branded. Or this is what you called etched ?
This ringcode type is more complicated. First of all, IR0b0t insisted these should be treated like laser-branded ones. Second, these can also have toolstamps written in a slighty different way:
Notice the "3" and "4" digits are shifted down and were likely added after the main ringcode was written, so it's a toolstamp. They are also visually different a little when you look on the disc under different angles, they are somewhat darker. And I'm not sure it would be correct to put everything into the engraved section.