a contraction consisting of a word specially abbreviated in braille 

condition of being unaccompanied by additional letters, symbols or punctuation except as specified in 2.6, the "standing alone" rule; used to determine when a braille sign is read as a contraction 

designating contractions (other than alphabetic wordsigns) containing dots in both the top and bottom rows and in both the left and right columns of the braille cell 

designating a braille character containing dots in both the top and bottom rows and in both the left and right columns of the braille cell, which therefore is physically unambiguous 

an unbroken string of braille signs, whether alphabetic or non-alphabetic, preceded and followed by space (also referred to as symbols-word)