The Editor’s Manual
Free learning resource on English grammar, punctuation, usage, and style.
Prepositions with overlapping meanings: In/into/inside/within, in/during, for/since, on/upon/onto, over/above, over/more than, under/less than, below/beneath/under/underneath, off/of, beside/besides, round/around, to/toward/towards.
Collective nouns such as “team” are treated as singular in American but plural in British English. It also depends on whether you want to refer to the group as a whole or to the individual members of the group.
Periods are not used in abbreviations with more than one capital letter, but contractions and other abbreviations with lowercase letters may contain a period (rtc., p.m., Dr.). No period is used after an abbreviated SI unit (kg, m).