How to interpret "LETTER-3-OR-MORE" on patent website (USPTO's TESS)?

Question

On the United States Patent and Trademark Office the Trademark Electronic Search System (TESS) has an entry for "SQL Server" that says

Word Mark SQL SERVER

And, then

Trademark Search Facility Classification Code LETTER-3-OR-MORE SQL Combination of three or more letters as part of the mark

Here is a screenshot,

How do I read that, does that mean the term SQL is Trademarked by Microsoft? Other queries for example "SQL Boost" and "SQL Sonic" make no mention of SQL and explicitly say,

NO CLAIM IS MADE TO THE EXCLUSIVE RIGHT TO USE "SQL" APART FROM THE MARK AS SHOWN

Others examples say,

NO CLAIM IS MADE TO THE EXCLUSIVE RIGHT TO USE "SQL" APART FROM THE MARK AS SHOWN

Going off this, should I assume Microsoft is making a claim at "SQL"?

Answer 1

According to this USPTO announcement eliminating the code, it’s an indexing system the PTO used back when trademark records were kept on paper. Trademark indexing is far from trivial, because trademarks are often designs instead of simple words or phrases. “Letters-3-or-more” seems to mean “the mark is filed under ‘3 or more letters in sequence.’” Searches on TESS show that the exact indexing isn’t exactly applied with great consistency (marks with more than 3 letters are sometimes indexed under “single letter”), but in any event it’s just a filing/indexing system. It doesn’t determine what the actual trademark is, it’s just meant to make it easier to find similar trademarks in USPTO’s files.