Recently noticed "OU Fish" on Worcestershire sauce.
Can it be used on fleish/steak?
The OU site has an article on this. The explain:
Therefore, products that contain amounts of fish that are not batel b’shishim must be labeled OU Fish, so that consumers will not unwittingly eat the product together with meat. If the amount of fish in the product is batel b’shishim, we do not require the product to be labeled OU Fish, provided that the fish ingredient is mentioned somewhere on the packaging. In this way, those who wish to be machmir for the opinion of Taz can do so by scanning the ingredient label. If the fish ingredient is not listed on the label or is ambiguous, (Omega-3 oil) then the product should be labeled OU Fish.
They seem to say that your Worcestershire sauce should not be eaten with meat, unless it's the label omits the fish ingredient (or it's ambiguous like Omega-3 oil), in which case you could eat it with meat unless you're stringent to pasken like the Taz.
So check the label, and then - based on your Minhag and the ingredients - you'll know the answer.
BTW: Anchovies are small, common salt-water forage fish of the family Engraulidae. The 144 species are placed in 17 genera; they are found in the Atlantic, Indian, and Pacific Oceans, and in the Black Sea and the Mediterranean Sea. Anchovies are usually classified as oily fish.