FMSY is taken from the operating model stored at DLM@OM$FMSY
FMSYref75(x, Data, reps = 100)A position in data-limited methods data object
A data-limited methods data object
The number of TAC samples
Note that you can out-performm this method easily. The requirement for fixed F is actually quite strict and is by no means the upper limit in terms of yield. Don't panic if your method beats this one for yield!
Interesting that the reduction in yield is no way near commensurate with the reduction in F as predicted by a yield curve and expressed in the pretty good yield theory.