In the US, putting the work in a tangible medium causes it to be fully protected. No "Copyright" required. [1] And, in addition to circle-c, any of these are v

In the US, putting the work in a tangible medium causes it to be fully protected. No "Copyright" required. [1] And, in addition to circle-c, any of these are valid substitutes in the US for the symbol, according to [2] 2204.4(A): • The letter c with a parenthesis over the top. • The letter c with a parenthesis under the bottom. • (c • c) • (c) • The letter c with an unenclosed circle around it. [1] https://www.copyright.gov/help/faq/faq-general.html#mywork https://www.copyright.gov/help/faq/faq-general.html#mywork [2] https://www.copyright.gov/comp3/ https://www.copyright.gov/comp3/