Partially correct. It is the N scale equivalent of Free-mo but there is no standard size module (unlike NTRAK). It is a truly free form modular system where modules can be any size or shape you like. Can be single or multiple line and tracks don't have to be down the middle. The only hard and fast rules to adhere to are DCC, code 55 track (or smaller) and standard physical and electrical connections between modules.
Cheers
David
The Free-mo module ends are basically the only specifications, with minimum curve radius, maximum grade, and rail height being the other standards. Within a Free-mo module set (most have a set of sections to make up a Free-mo module for easier transportation), the internal section joints do not have to be compliant. The result is excellent flexibility in design, a push for more prototypical single track operations, and less round-and-round operations.
The width issue has been a point of discussion on the HO Free-mo group at
Free-mo : Discussion in English of HO scale Free-mo and Fremo modular model railroad concepts. (you have to join to post, but it's free). Consensus was that the 24" width applied across the fascia to minimize the visual mismatches. To match an existing 12" deep shelf, one could easily use 12" long (or longer) adapter section with width tapering from 24" to 12". This also gives some space to move the track to the correct location at the Free-mo end.
Free-moN standards are here:
Free-mo Standards N
A word of caution. There is a North American Free-mo standard, and a European Freemo (sp?). The 2 are similar, but are not the same.
The European version uses a series of standard profile end plates, which are generally pre-manufactured. Europe also runs the rails right to the module edge.
The North American Free-mo uses fitter rails (2" in HO) and a single flat profile end plate design. Digitrax DCC is also standard. I know some Free-mo modules are fitted for both Digitrax and NCE DCC throttles - NCE at home and Digitrax at setups. I think that with careful wiring that the throttle plug-in plates can be used by either make throttle.