I'm working on a lighting product catalogue with products from many overseas suppliers. In regards to colour temperature, some of them put a space character before Kelvin symbol, some not:
4000K, 5600K
or
4000 K, 5600 K
Is there any official recommendation here?
Edit: It was suggested that this question is a duplicate of similar question related to computer symbols, suggesting it depends on style, and I happily agreed and considered that question as answered. However just now I've just found that there actually is an official recommendation related to SI unit symbols. Which makes the situation different than with units of computer storage.