1990, Concise Oxford Dictionary of Current English, 8th ed., Oxford: Clarendon Press:
Brit. indicates the use is found chiefly in British English (and often also in Australian and New Zealand English, and in other parts of the Commonwealth) but not in American English.
1991, Collins English Dictionary, 3rd ed., Glasgow: HarperCollins Publishers, p xvi:
Brit. [. . .] mainly to distinguish a particular word or sense from its North American equivalent or to identify a term or concept that does not exist in North American English
1994, Merriam–Webster's Dictionary of English Usage, →ISBN:
454: Let's begin with a cursory glance at British English. [. . .] Our only two fairly recent examples of Britishfolks—and these both from Commonwealth sources—are of this construction: [followed by quotations from Australia and Barbados]
611: In the following examples, the first three are British, in the broad sense that comprehends the Commonwealth nations: one locates a place, one a thing, and the third might be intepreted either way. The rest of the examples are American. [followed by quotations from Doris Lessing, Zimbabwe, and J. Stevenson-Hamilton, South Africa, and Stuart Cloete, South Africa]
730: Persevere may sometimes be used with with; although it is found in American English, it seems more often to occur in British and Commonwealth English:
2004, “Guide to the Use of This Dictionary” in Canadian Oxford Dictionary, 2nd ed., Don Mills: Oxford University Press, p xvii:
Brit. indicates the use is found chiefly in British English (and often also in Australian and New Zealand English and in other parts of the Commonwealth except Canada) but not in North American English.
2009, “Guide to OED Entries: Overview” in Oxford English Dictionary Online, Oxford University Press:
The varieties of English covered include British English, American English, Australian English, New Zealand English, the Englishes of the Indian subcontinent, Southern Africa, and the Caribbean, among others.