capitalization - Should I capitalize "all" in titles?

Let's say I have a title "full legal names of all sellers"

Should I capitalize it as

a) Full Legal Names of all Sellers

or

b) Full Legal Names of All Sellers

?

I have doubts as "all" is not a noun here but rather a modification for a noun "sellers". Am I wrong?

And yes, I've read Which words in a title should be capitalized?

Answer

The short answer is yes, and here's the reasoning:

In a title, adjectives, verbs, pronouns, etc. (pretty much all words except for prepositions and articles, such as the and an) are capitalized. As you said, all is modifying the word sellers. That makes all an adjective, and it would, therefore, be capitalized. Full and legal are adjectives as well, and see how they are capitalized as well.

Let me know if you have any questions!