I'm guessing you mean 350F, which is gas mark 4.
On an US coin it can mean "cents" or it can be the mint mark of the Charlotte Mint, which existed only from 1838 to 1861.
Mark C. Honeywell was born in 1874.
Mark C. Honeywell died in 1964.
Mark C. Taylor was born in 1945.
Mark C. Hunter was born in 1974.
Gas mark 9 is equivalent to 260°C.
Mark C. Smith was born on 1940-09-10.
Mark C. Smith died on 2007-03-27.
Mark C. Johns was born on 1952-11-29.
Mark C. Lee was born on 1952-08-14.
The CE mark is used for all products in the European Union - it means it conforms with certain regulations. See: http://en.wikipedia.org/wiki/CE_mark :)