As I know, dependent clauses must be separated with a comma. Below are 2 sentences from the University of Leicester website. I don't understand why there are no commas where I expect them. Are these sentences just wrong or is it something specific to British English?
When including a number in a file name [no comma] always give it as a two-digit number rather than one, i.e. 01, 02 … 99, unless it is a year or another number with more than two digits.
If using a date in the file name [no comma] always state the date ‘back to front’, and use four digit years, two digit months and two digit days: YYYYMMDD or YYYYMM or YYYY or YYYY-YYYY.
Another sentence on the same topic, from the different website; again, the author speaks British English:
Long file names are more difficult to remember and recognise. Some words add length to a file name but do not contribute towards the meaning, for example words like “the”, “a”, and “and”. Where the remaining file name is still meaningful within the context of the file directory [no comma] these elements can be removed.
Or maybe these sentences are OK even in American English?