--Include a little badge of what the item type is in the item deion. Something like the Broken Heart Shards sure don't look like food items, and the deion says nothing of it being edible, yet they are consumable and part of food items/nourishment. And again, something like the Blue Water Bottle (which is sold in a shop where everything is food but these water bottles) is not consumable. (I believe the water bottles are also a part of the food quest but cannot confirm at this time, my memory could be wrong). 

--Follow up thought from the last point - perhaps in the item database an item could say if it could be asked for in a certain quest or not. (Thinking of items that will stock in the food shops and are legendary like the Cucumber, but I assume those will never be a part of the Food Quest). And/or perhaps you could check the rarity of an item you own right from your inventory, or even be able to sort by rarity like you can in NPC shops. 

--Include in an item's deion what it might do if it isn't already stated. Dye kits are nice in that way because they specifically tell you what will happen, but something like Ice Apples do not say what they do in their deion and can be easily missed. Also things like Alert items don't seem to say what they are used for in their deions.

--(tentative suggestion, not sure if this would be too useful) Include a 'Quest' item sub-section (like we have food, weapons, etc.). For items like the planet activities (like bird catching). Again, there may be others I can't think of, but I think this could potentially be useful. I guess there could also be other sections instead of 'quest' but it feels like we have a tooon of items dumped into the 'Other' category. I do notice that in the item database there are items like the Curse of the Undead who have a special type (like the curse having 'Heal' listed as its item type), so I wonder if this could also be included in inventory sorting purposes. 

Relking Coins can be converted all at once tle="" target="_blank">here. There is a similar link in the bank for Barter Tokens.

The Item Database provides information if an item is a food, toy, etc -- tle="" target="_blank">Broken Heart Shard example. This information is also provided in a pop-up when clicking an item in an NPC shop.

Library is, as stated in the SB, found under Activits > All > Collecting.

Even so, it still seems a bit strange that it's not listed as food anywhere on it, and those aren't sold in the NPC shop so that's not exactly helpful either. Maybe that pop-up could be included in the inventory too? But I could see that getting annoying. 

Also thank you for that, still keeping that up as an edited suggestion of moving the Library/Squishy Shelf links into the inventory with Clothing Rack.