I posted in the bug forum several months ago, when the compendium layout was changed, about how the compendium for 5e lacked any mention of concentration on spells that required it, instead simply saying 'Yes' after one of the detail lines at the top. While very inconvenient, it at least had the relevant information. Now, however, there are no details about concentration on ANY of the spell cards at all, which means that if anyone wants to use the roll20 compendium in a game to look up a spell, they will always be missing relevant information. At the moment, they're forced to use a different resource, such as a physical book or D&D Beyond if they simply want to know how to use their spells correctly.