If it was already the name of a registered British ship; if it was a name so similar to that of a registered British ship as to be calculated to deceive or likely to confuse;
if it was a name which may be confused with a distress signal; if it was a name prefixed by any letters or names which could be taken to indicate a type of ship or any other, word, prefix or suffix which might cause confusion as to the name of the ship; if it might cause offence or embarrassment; or a name which has a clear and direct connection with the Royal Family.