I want to ensure a list of strings is sorted following a custom pattern

Question

I want the list to be in this order ['PRE','IMP','POST','BO']

Where the actual list will have duplicates of each e.g.

Desired List

list = ['PRE', 'PRE', 'PRE','IMP', 'IMP','POST','BO', 'BO']

A possible out of order list:

list = ['IMP', 'PRE', 'PRE','IMP', 'IMP','POST','BO', 'BO']

I want to simply write code to check that the entire list follows the sequence order.

if list is in order:
    print("correct")
else:
    print("incorrect")