See a listing of genealogy abbreviations at Rootsweb http://www.rootsweb.com/~rigenweb/abbrev.html

Some frequently requested abbreviations are:

INST –  Instant which means “present, current; as in the instant case we are considering; …used with date to indicate the current month; as the 10^th inst.; the 8^th of this instant June; Also means…This month, when term used in 18^th or 19^th century death notice, it refers to the month in which the item was published; for example: “Died on Tuesday morning, 4 inst…”, would mean that the person died Sept. 4, 1849, since the newspaper was dated Sept. 8, 1849.  (from OGS Newsletter, July 1984, p5.

ULT – Ultimo which means “in the month preceding the present” ; In the month preceding the present

PROX – Proximo which means “in or of the next month after the present; as t he 3d proximo. ; In next month

INT – Intestate, died without a will

Do – ditto

See also Researcher’s Guide to American Genealogy by Greenwood, http://coolcat.org/search~S1/t?SEARCH=researchers+guide+to+american+genealogy pp18-19. (copy in Local History behind the desk) and

The 1910 Census Catalogue, pp. 40-42 also has abbreviations as used in soundex/miracode. (copy kept in Local History)