Do you mean karmadhārya [samāsa]? - No idea about the word itself, though.
My humble contribution is vanquished by later efforts.
Back in the '70s I wrote & maintained the programming which produced the price tags for a couple dozen retail chains. In many cases the magic 10-letter words were made up words.
I wrote a quick little perl script to list them:
perl -ne 'chomp; next if ! /^[a-z]{10}$/; %a=(); for (split //) { $a{$_}++; } if (keys %a == 10) { print "$_
"; }' /usr/share/dict/words
Unfortunately, the output’s a little too long to list. It came up with 2513 words, and that’s less than complete since some words (such as chamberpot) weren’t in the source wordlist.
Here’s the output: http://angband.org/~erasmus/tmp/10letters.txt
I’m thinking that it would be pretty easy to find two words that have ten different letters.
You must have worked in the same store I did. 
Can someone explain the use of ten letter words in price coding?
I’m very confused by this whole discussion, what exactly is the practice that is being referenced?
Some shops used to mark goods with both the retail and the wholesale price, with the latter intended for their own accounting purposes, but coded to hide the wholesale price from the customer. (Though since it was a simple substitution code, and the retail markup was always roughly the same, it was an extremely easy code to break.)
So if retail was $1.99, wholesale was $1.40, and the code was A for 1 through to J for 0, you might have:
$1.99
A.DJ
Insurance. Rules and regulations are my life. 
Gotcha. Thanks!
And now a crescendo from the anvil chorus! That was the one that we used for the end-of-year inventory in the store.
Whenever stock was received from a supplier, the clerks of the toy/stationery/ newspaper/mags/comic store had to use a greasepencil to mark the wholesale price code on each item (except where it would be unneeded or would damage it, like on magazines), but numbers were used for fractions - 15 1/3 cents became bk 1/3. The clerks and some kinfolk part-timers like me had to count everything in the store over New Year’s and then tabulate them with unit/extended costs, all on columnar pads by hand. **Cal Meacham **might remember the store, if he’s old enough and been where he is, long enough.
Like I said in the OP, I knew there was another such word(!), but had forgotten what it was and have been wondering about it (off and on) for many years. It may have been “regulation” but it was a long time ago, like, long B.C. and B.W. (Before Wal-Mart).
**Panurge - Yes, I’m guilty of having misspelled it. My bad. **- karmadharaya in my Webster’s means a word made up of an adjective followed by a noun. Like “blacksmith”. What’s “samāsa”?
Erasmus Darwin - “perl script” is way above my pay grade (and IQ). But 2,513 of them - that’s awesome.
Thanks for all the others, guys/gals. I never thought there were so many. I guess I never really thought about it enough.
Here’s the individual list:
background
bankruptcy
blacksmith
blathering
blockheads
chamberpot
configured
defoliants
discourage
dumbwaiter
fruitcakes
hyperbolic
hysterical
infamously
nightmares
overpaying
presumably
regulation
polygamist
upholstery
and Erasmus Darwin’s 2,513 minus the above.
Gee, I can make at least one nearly intelligible sentence out of several of the above listed words in consecutive alpha order! (Chamberpot configured defoliants discourage dumbwaiter fruitcakes.)
I must get a life.
REIMPLANTS
ANGIOSPERM
both user one letter from each column on a QWERTY keyboard.
Samāsa is the Sanskrit term for “word compound”, a class of which is called karmadhāraya. The karmadhāraya samāsa works pretty much as you have described it. I had no idea that the term had found a use in the English language, hence my question - I thought the dope had provided me with a fellow Sanskritist…