Code 10/4 is a broad and simple signal. The signal suggests that all is not well. There is no indication why things are not well. This could be asked in direct question: 'What is the matter?' There are other codes which are much more specific as to why things are not right. These could be used directly without ever using 10/4. There is, however, a value in having 10/4 as a generic response. It may be easier to remember than all the other codes. There might be some point in using a double code. For example, someone might say: 'Code 10/4 and code 10/5.' This means: 'I am not happy because I am too busy and overworked.' There is not much advantage, however, in doing this rather than just using 10/5 on its own. There may be the value of emphasis. Where the nature of the 'not well' mood cannot be defined by any of the other codes, then the general nature of 10/4 becomes an advantage.