On Facebook, the letter “H” can refer to a few different things, but it is commonly associated with “H” being used as shorthand for “Hours.” In certain contexts, especially on mobile devices or in business pages, you might see “H” when discussing operating hours of a business, such as “Open H” or “Close H” indicating the times the business is open or closed for the day.
If you are referring to specific features or contexts on Facebook where “H” is used, could you clarify? For instance, it might also appear in relation to reactions, posts, or other functionalities, and I’d be happy to elaborate further based on that context!