If you're talking clearly marked B100 (100% biodiesel), that's one thing - but it seems a lot of stations now blend it in and the people behind the counter will usually have no idea what the actual percentage blend is.
B5 and B20 (5% bio / 95% petro and 20% bio / 80% petro) have been pretty commonly labeled as options on the pump in my experience.
Please note that biodiesel is NOT vegetable oil and even running 100% biodiesel, your exhaust is not going to smell like french fries. That's for the folks burning WVO or SVO (waste and straight vegetable oils). They need conversions on their engines if they expect them to keep running for long.
Biodiesel has been chemically modified to be 100% compatible with any diesel ever made, if not the rubber seals and hoses of some older ones. It does a lot to restore the lubricity of ULSD, and will also do a hell of a job cleaning any sludge and deposits out of the system so if you're starting to run high percentages of bio on a vehicle with a bunch of miles on it, you may want to change fuel filters more frequently for a while as that stuff gets cleaned out and caught up in the filter.
I try to make sure each tank has some bio in it for lubricity, if not I'll add some 2 stroke oil. And if your fuel ever gels, no biggie, just warm the vehicle up or add some diesel 911 to the tank and filter. Unless of course you're stranded somewhere without those options - then it'll seem like a biggie :ylsmoke: