# conventions - The plural of Gray (Gy) is Gray. - Following [International System of Units - Wikipedia](https://en.wikipedia.org/wiki/International_System_of_Units#:~:text=The%20SI%20comprises%20a%20coherent,candela%20(cd%2C%20luminous%20intensity)) there should be a space between the value and the unit. e.g. 20 Gy not 20Gy - The standard unit of length is metre. - Use mm and not cm when defining small lengths. - Use male and female as descriptors, not nouns. - e.g. The male doctor saw the 28-year-old man. - Following [ISO 8601 - Wikipedia](https://en.wikipedia.org/wiki/ISO_8601) for dates: YYYY-MM-DD - An initialism is where the letters are read out, while an acronym is pronounced. - e.g. OAR is an initialism, but VMAT is an acronym (when pronounced vee-mat). - When pluralising either an initialism or acronym, the letter s can be added at the end (without an apostrophe). - Interestingly SIB is an initialism in Australia, but an acronym in the UK. - Source: [How to pluralize the following initialism - English Language & Usage Stack Exchange](https://english.stackexchange.com/questions/443474/how-to-pluralize-the-following-initialism)