I see that some spells in the dndbeyond spell list have an icon of a diamond with a c in the center next to the spell name and the duration. Would like to confirm that means the spell requires concentration, or is it something else entirely?

Are there other symbols that might not be obvious that I should know about?

Thank you!

Figured this out by looking at the advanced filters. All set here!

Glad you figured it out. C for concentration and R for ritual took me a while to figure out when I first started using this site