I have a question about the two examples below. From what I can gather is that these two preform the exact same task, that is to deny updates for this network with mask greater than /23.
If this is correct, which is the more standard/preferred practice, ge or le?
ip prefix-list test seq 5 deny 188.8.131.52/23 le 32
ip prefix-list test seq 5 deny 184.108.40.206/23 ge 24
Correct. As long as the range you are using is the same (i.e. 16 to 32 for both ge or le), the results will be the same either you use the GE or LE form.