question on 9 pin cables

[riverman]

Just going thru my collection of cables.My question is some say nm (null modem I presume) others say nothing.Am I safe to presume that if they are not marked they are straight thru or are there other types of similar cables.

[calin]

Some cables are marked -usually not- the best way is testing them with an VOM, the straigth through should mark continuity in ALL pins!!! The Null modem got some crossed ones.