Recently, a change was made in D&D Beyond's builder in Sources, adding two different options for 'Expanded Rules,' with the descriptions given in the Builder as follows:

Homebrew: Character options designed by other players and uploaded to D&D BEYOND. Talk to your DM before including Homebrew content.

Core Rules: Character options from the Player’s Handbook, Dungeon Master’s Guide, Monster Manual, and D&D Beyond Basic Rules.

Expanded Rules: Character options from supplementary sourcebooks beyond the Core Rules.

2014 Core Rules: Character options from the 2014 Player's Handbook, Dungeon Master's Guide, Monster Manual, and Basic Rules.

2014 Expanded Rules: Character options from supplementary sourcebooks such as Tasha’s Cauldron of Everything and Xanathar’s Guide to Everything, that are beyond the 2014 Core Rules.

Legacy/Noncore: Character options from older sources that may conflict with the Core Rules. These include sources that are out of print or created for charity.

I notice that 'Expanded Rules' is the only category without any examples of what books fall under that description. What exactly is the difference between Expanded and 2014 Expanded? The creation of the new category implies 2014 Expanded content will soon become Legacy content?

Now, on the cover of several books in the marketplace, like Book of Many Things but also Tasha's and Xanathar's there's huge bold text saying COMPATIBLE WITH THE NEW CORE RULEBOOKS. However, Tasha's and Xanathar's are specifically listed as examples of 2014 Expanded Rules. Monsters of the Multiverse, on the other hand, lacks this text on the cover entirely, so I assume that entire book is Legacy content.

What does it mean for something to be '2014 Expanded Content' if it is still compatible with 2024 Core? Shouldn't it all just be 'Expanded Content'?

Can someone tell me, or point me to, an official list of what books are 2024 Expanded, versus 2014 Expanded, versus Legacy?

Expanded Content is to 2014 Expanded Content as what Core Rules is to 2014 Core Rules. ie they're both the same type of book (supplementary character options beyond the Core Rules that doesn't fall under legacy, noncore, homebrew, or partnered content). The only difference is 2014 Expanded Content was printed before the 2024 Core Rules and Expanded Content was printed after.

2014 Core Rules >>>> 2014 Expanded Content >>>> (2024) Core Rules >>>> Expanded Content

For example, the two new Forgotten Realms books would fall under Expanded Content

Thanks for the reply, I have two follow-ups/clarifications:

1. So right now, there are no books that are 'Expanded Content' until the new FR books come out? Currently everything is '2014 Expanded Content'?

2. If the distinction is strictly for publication date/organizational purposes, and the 2014 is all compatible with 2024 Core, why create an in-builder distinction? From a character generation mechanics perspective, a WoTC book is either Core, Expanded or Legacy (it's okay if the answer is "there's no real reason" or "for OCD purposes" or "there might be no reason now, but as more books come out the distinction is likely to be important" but the fact they created a whole new 'Sources' category in the character builder was what confused me in the first place).

Thanks again!

Quote from Roll_Models>>

Thanks for the reply, I have two follow-ups/clarifications:

1. So right now, there are no books that are 'Expanded Content' until the new FR books come out? Currently everything is '2014 Expanded Content'?

2. If the distinction is strictly for publication date/organizational purposes, and the 2014 is all compatible with 2024 Core, why create an in-builder distinction?

 Because some people want to only use 2014 rules, so they want to be able to disable all 2024 releases. Or vice versa, some people want to use only 2024 content so want to disable all 2014 books.

An addition to point 2's answer: The content in those books is only compatible to be used on 2024 characters until an updated printing for the 2024 rules releases, like it already did for a few of the subclasses. For instance, the Soulknife in Tasha's can't be used with the 2024 Rogue because the 2024 PHB printed a 2024 version of Soulknife.

Is it in general possible for a 2014 PC to use the Extended Rules (2024) for example from heros of faerun?
It seems not to work.

Example:
My bard is able to add the spell Yolande's Regal Presence ( from 2024 PHB )
but is NOT able to add the spell Cacophonic Shield (from Heros of Faerun )

is this a bug?

Quote from TyReg >>

Is it in general possible for a 2014 PC to use the Extended Rules (2024) for example from heros of faerun?
It seems not to work.

Example:
My bard is able to add the spell Yolande's Regal Presence ( from 2024 PHB )
but is NOT able to add the spell Cacophonic Shield (from Heros of Faerun )

is this a bug?

 No apparent bug as I'm able to add both spells. I needed to enable Expanded Rules (not 2014 Expanded Rules) but once I did the spell shows up as a choice for my 2014 Bard.

Worth pointing out that there is one spell from Heroes of Faerun that does have a bug in this area. Wardaway has erroneously not been added to the spell lists for the 2014 classes and so won't show up for them no matter what options you select for Sources. Unfortunately, until they fix it, there's nothing you can do about this other than creating a homebrew copy.

However, as far as I can tell this is the only spell that has this problem; Cacophonic Shield is on the 2014 classes' spell lists.

Is your bard really 2014? I created a New charakter to check. Didnt work again. Is Heroes of faerun maybe not added to my account correctly? I can See the content when i open it in library

Quote from TyReg >>

Is your bard really 2014? I created a New charakter to check. Didnt work again. Is Heroes of faerun maybe not added to my account correctly? I can See the content when i open it in library

Well, do you actually own the book? If you don't, but only have access to it through content sharing, then you will only be able to use character options from it on a character that's actually in the campaign where the book is being shared.

Quote from TyReg >>

Is your bard really 2014? I created a New charakter to check. Didnt work again. Is Heroes of faerun maybe not added to my account correctly? I can See the content when i open it in library

 If you look at the icon, it's the 2014 bard class (it's why I made a point to include it in the screenshot)

I dont know how to add pictures here. but i did a test and created a 2024 bard, level 10. 
home screen i enabled extended rules. but under spells i dont even see the filter option, only "core rules" and "critical role"
if i enable extended rules 2014 i indeed find it.

2024 Bard, level 10, all core 2024 books and the Heroes book owned.

Expanded Rules checked, 2014 Expanded Rules unchecked, Cacophonic Shield and the Expanded Rules filter both appear.

Check your settings again or upload an image to something like Imgur then link it if you need to.

Quote from TyReg >>

I dont know how to add pictures here. but i did a test and created a 2024 bard, level 10. 
home screen i enabled extended rules. but under spells i dont even see the filter option, only "core rules" and "critical role"
if i enable extended rules 2014 i indeed find it. 

In your previous post you said

Is it in general possible for a 2014 PC to use the Extended Rules (2024) for example from heros of faerun?
It seems not to work.

Which is it? 2014 or 2024 bard

Quote from wagnarokkr >>

Quote from TyReg >>

Is your bard really 2014? I created a New charakter to check. Didnt work again. Is Heroes of faerun maybe not added to my account correctly? I can See the content when i open it in library

Well, do you actually own the book? If you don't, but only have access to it through content sharing, then you will only be able to use character options from it on a character that's actually in the campaign where the book is being shared.

 That was indeed the reason.
normally i own the books and share with my friends.
i thought it was one of the free books added.
looked under library i figured out it was only shared with me.

thanks for your help guys.