I'm looking for tires for a set of 700c Zipp 808 tubular rims.

Looking at PBK they have the Vittoria Corsa Evo CX 700 x 21mm in black, while some other colors are listed as 700C x 21mm. I thought the letter (width designator) no longer mattered for tubulars. These are the same sizes, yes (700 vs. 700C)?

Thanks