Have a doubt on it, imagine we have the following d-list:
frame-relay de-list 1 protocol ip list 135
which is using this acl:
access-list 135 permit tcp any any eq telnet
I understand that after applying it to the frame relay interface all the traffic destinated to port 23 is going to be marked as "discard elegible" and the rest of the traffic will fall in the deny ip any any implicit so won't be marked. Also it won't ever affect to normal IP operations, I mean, Ii doesn't work at the same time as a real ACL denying everithing that goes out of the serial interface, right?
You are correct on both questions.
All port 23 traffic will be "marked" DE.
A DE list has nothing to do with dropping traffic, it just marks or doesnt mark traffic.