FMSY is taken from the operating model stored at DLM@OM$FMSY
FMSYref(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-perform this MP even though it has perfect information of FMSY and current abundance. The requirment 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, especially for short-lived species of high temporal variability in productivity!