Understanding The Words - All Different - For A Stamp Collector .

Many times on stamp chat rooms I bring up these words ---Is it all different ?
These are important words that we see especially for stamp auction firms and missing when a huge collection is written up in their catalogs . It is the two words stamp collectors don't make clear in their discussions here when talking about worldwide collections .
The question I like to enject into the same discussion is are they ALL-DIFFERENT . ?
What is not clear is it Trash Bags filled with stamps on paper in someone's garage or a humid dirty basement . We now are seeing 1,000,000 stamps on pallets of sheets of stamps still wrapped in the printers plastic wrap . at stamp auctions ,so a collectors can claim his collection has a million stamps but fails to announce he bought it at a stamp auction for $1,400.00 plus $2,000 dollars shipping it to his house .

So to be clear what is --ALL DIFFERENT ?
Does it include watermarks differences and does it include perforation difference . Then the area of color or shade difference ?
For us it is easy to agree on watermarks in the paper and also perforations differences . Shades of color becomes more of a problem because to be sure or to follow what is published , I would need over 200 different catalogs of each country ,plus special research booklets just to have a reference library.
Then we come to the attitude of collecting what you want and how you want in the hobby and which everybody agrees on .

So some day in the future ,hopefully will be able to change that claim of 330,000 all different to number like 400,000 in a few years because of pages like this .

I'm willing to go well beyond perfs, watermarks and papers.

If someone has taken the time to find identifiable features (other than damage) that show "these two/five/ten stamps are not the same, because..." those are probably going to count as "all different" in my eyes.

A sequential collection of numeral cancels, from any number of early issuers? All different.

Early stamps of Danzig, with thirty different postmarks? All different (and not easy to do).

Penny Red plate number collection? All different.

KGV Jubilee plate flaw collection? All different.

Canadian re-entry collection? All different.

At the end of the day, it doesn't matter. A person can go as deep as he or she wants, to the point of creating new reference material, and a friend of theirs can collect face-different topicals. Everybody's happy.