"reticulate" means "net-like" and describes the body patterns of some snakes(what reticulated_python are named after) and especially giraffes:
post #4029431 post #4429906 post #4193987 post #1969321
So it would be a pattern tag similar to stripes or spotted_body- in a sense it's the opposite of spots where the lines around them are actually the pattern. But reticulation, reticulated_fur, reticulated_scales and reticulated_body are all marked invalid and reticulated is empty.
Is this the result of some past decision or just something nobody's felt like tagging before?