Abbreviations beginning with a

APTTActivated Partial Thromboplastic Time
Miscellaneous » Unclassified

APTTAAfghanistan-Pakistan Transit Trade Agreement
Business » International Business

APTTAAustralasian Piano Tuners Technicians Association
Community » Associations

APTTAAustralasian Piano Tuners and Technicians Association
International » Asian

APTTAAfghan Pak Transit Trade Agreement
Miscellaneous » Unclassified

APTTAAfghan Pakistan Transit and Trade Agreement
Miscellaneous » Unclassified

APTTAAfghan Pakistan Transit Trade Agreement
Miscellaneous » Unclassified

APTTAAfghanistan Pakistan Transit Trade Agreement
Miscellaneous » Unclassified

APTTAAndhra Pradesh Table Tennis Association
Sports » Tennis

APTTPAlabama Prospective Teacher Testing Program
Miscellaneous

APTTTAssociation of Professional Theatre Trainers and Teachers (Canada)
Community » Associations

APTTTAssociation of Professional Theatre Trainers and Teachers (Canada)
Community » Educational

APTTTAssociation of Professional Theatre Trainers and Teachers (Canada)
Community » Performing Arts

APTTTAssociation of Professional Theatre Trainers and Teachers (Canada)
Community » Theater

APTTTAssociation of Professional Theatre Trainers and Teachers (Canada)
Regional » Canadian

APTUAntwerpse Provinciale Taxi Unie (Dutch: Antwerp Provincial Taxi Union; Antwerp, Belgium)
Academic & Science

APTUAfrican Postal and Telecommunications Union
Community

APTUAsia Pacific Taxpayers Union
Community » Conferences

APTUAssociation of Public Transport Users
Community » Associations