US 93 and 95 use different exit tags for their overlaps on I-11 and 515.
93: x-y(z)
95: z(y)
I prefer the x-y(z) format as it quickly spells out the dominant route's classification, but both routes should use the same format, regardless of which one it is.
Having to use both I-11(15b) and 15b(11) for the same point is a bit ridiculous. Should codifying one as standard be needed? (Outside of I-105/OR 126, I use the x-y(z) format; 105/126 both share a 0 for the overlap, so neither route references the other for their exits).
Sidenote: CA 99 uses both formats still -- I-5(221) and then z(y) for the US 50[Bus 80/I-305]/I-5 overlap in Sacramento.