Glenn Ashmore wrote:
And whose fid? Most splicing instructions say "measure x fid lengths" but
seldom state it in inches or rope diameters. There are several makes and
different lengths of each but there are less fid sizes than there are rope
sizes so how would you define a "fid length"?

When I splice NE Rope with instructions from NE Rope, I use a NE Rope
fid to measure.

IIRC, the instructions are often given in terms of rope diameters.