Use of the trademark symbol is optional, but it doesn't hurt. For logos it's often part of the image file, so it would actually be more work not to use it.
This page is full of reasonable examples. In the banner we have the Answers logo with TM, and at the very bottom we have a copyright notification, but for running text including the word "Answers" (such as the Answers Properties list header and content), there are no markings.
Other websites are almost cartoonishly consistent with their use of the symbol--every logo, every slogan, every time the name of the company or its products appear, there's a helpful (r) reminder in case you'd forgotten in the intervening half-inch that they've registered it all. These are cases where using the indicia is distracting.
What you want is a balance.
No, but you may wish to trademark elements of it (the URL, logo, slugline, etc) if you plan to use them in commerce.
Assuming you are referring to the social networking website, the name "twitter" is a legally registered trademark so it should be used with the ® symbol.
The Unicode for the Trademark Symbol is a symbol used to make the assumption that the previous mark is a trademark (a trademark is a recognizable sign of a particular company).
Trademarks are a bit misunderstood. Trademarks are adjectives and not nouns, so when you refer to a company by its name, you do not need to use the trademark symbol. For example, Answers Corporation is the name of the company that runs this site. If you refer to Answers Corporation in an article, you should not use the trademark symbol. However if you say something like, "The Answers.com(SM) website is . . . ", then you should use the trademark symbol. It is often customary to use a trademark symbol in the title of an article (if applicable) and then the first time that the trademark appears in the article. It is generally accepted that you do not need to use the symbol each time the trademark appears. Michelle_Esq IP attorney with 15 years experience
In order to use the trademark symbol, you need to have registered the design with the trademark office. When you license your image for use by the band, you can specify, for example, how large the trademark symbol must appear, etc.
Facebook is a registered trademark, which earns it the right to use the ® symbol.
You can use the trademark ™ symbol on any unique name or logo you created and use. It does not require special registration yet still signifies your ownership. The Registered symbol ® is similar to the trademark symbol but it requires registration with the U.S. Patent and Trademark Office (USPTO or PTO). The copyright symbol © is similar to the trademark symbol and does not require registration (though it is recommended), however it is for use on intellectual property as opposed to brand names.
.
Often the (r) symbol is considered part of the trademark and always appears with it; this is certainly the case with logos.
The 'R' symbol goes after the trademark or logo.
One can find the US trademark symbol from the USPTO's Trademark Electronic Search System (TESS) database for free. One alternative you can do is to hire an attorney to make the search for you.
The little TM symbol in a circle represents a trademark. It indicates that the word, phrase, logo, or symbol that it is associated with has been registered as a trademark to protect it from unauthorized use. It signifies ownership and asserts the rights of the trademark owner.
Typing (r) should autocorrect to the registered trademark symbol.