ENlarger bulb for Ilford MG-600

I have an Ilford MG-600, and this past weekend, the bulb died. I had some spare bulbs in a drawer, but when I looked at them more closely, I saw that some of the bulbs were listed as ELC, 24V, 250W, and two were ELC/C, also 24V, 250W. Do any of you know if there is a difference between these bulbs? The enlarger manual specifies the ELC bulb, so I am wondering if I should just toss the ELC/C bulbs.


I notice that some retailers sell both.....

Mark