Country of manufacture, according to the Sony showroom where I bought mine.
Some price comparing website showed 3 versions of the FS76 - vanilla FS76, FS76U, & FS76TNS - a few weeks ago, might still. The info on the site said only the TNS was 100hz, which is ****ocks, amongst other things.
After some fretting, & ringing unbeatable.com (who did not know what the suffixes meant) & John Lewis, I ending up in the Sony Centre who told me all versions are the same, the suffixes just show the country of manufacture.
This is the answer that I got from Sony when I e-mailed them with the same question
Thank you for your recent enquiry.
This is a matter that can cause confusion from time to time. To clarify, the basic model number for the television in question is KV-36FS76. When it is manufactured and marketed for UK specification the 'U' is added. When retailers order the television, they have the option of stating whether or not they require a stand, and this is usually when the 'S' suffix is added. 'TNS' is again a code for dealer reference. Of course, all these variations differ from retailer to retailer.
The most important thing to note is that if the unit is purchased in the UK, and you hold a receipt as proof of purchase, your product is covered under the conditions of he Sony 12 month warranty.
For and on behalf of
Sony United Kingdom Limited