Back a few years I put several strings of Ikea 12V halogen track lights up over the layout; each track with 5 x 20W bulbs. They have been on dimmers since day 1 and work great. Then about 4 years ago I converted the halogen bulbs over to PAR16 6.5W LED lights which has been a great switch. A few days ago one track stopped working and it turns out the 105W electronic transformer in the control box had quit. I noted it is rated "for halogen lamps" which I did not know before; and it doesn't say "dimmable" or not. At the local light parts store I picked up a 70W replacement; put it in and all seems to be working fine again. It also says "for halogen lights", which seems to be common.
The question is what difference does a "halogen" rating make with these things, if any? If they are not to be used with leds lights, why not? And are there any adverse effects of using dimmers with them if they are not rated as dimmable? 
Thanks for any thoughts,
Rod
