See also: HABIT
MAILING–Custom and Practice; OTHER ACTS, TRANSACTIONS AND OCCURRENCES; PAROL EVIDENCE; ROUTINE PRACTICE
WORDS AND PHRASES.

1.  Establishing the Meaning of Terms

Evidence of an industry-wide custom will be admitted to establish the meaning of terms of art or even to establish undefined terms in some cases.{footnote}Mellon Bank, N.A. v. Aetna Business Credit, Inc., 619 F.2d 1001 (3d Cir. 1980).
 
See 23 ALR2d 244 (custom and usage in film, television and radio industries).{/footnote}  Note that the "best evidence" rule will preclude admission of such secondary evidence where it is being offered in place of an existing contract.{footnote}Amoco Production v. United States, 455 F. Supp. 46 (D. Utah 1977) .
See BEST EVIDENCE; WORDS AND PHRASES.  {/footnote} 

§ 2.  As Evidence of Conduct on a Particular Occasion
 
Evidence of an individual’s “habit” or a group or organization’s “routine practice,” offered to prove that the individual, group or organization acted in accordance therewith on a particular occasion, is sometimes referred to as evidence of “custom.”{footnote}William A. Schroeder, Evidence of Habit and Routine Practice, 29 Loy. U. Chi. L.J. 385, 388-89 (1998) (discussing Illinois law; recommending against use of “custom” in this sense).{/footnote}  See HABIT; ROUTINE PRACTICE.

1.  Proving Custom and Practice

Industry custom and practice may be proven through industry publications, which will not be considered hearsay when offered for this purpose.{footnote}Link v. Mercedes-Benz, 788 F.2d 918 (3d Cir. 1986).{/footnote}  Expert testimony is also allowed, so long as such testimony is limited to the customs and practices in the industry, and stops short of expressing a legal opinion.{footnote}Marx & Co. v. Diners’ Club, Inc., 550 F.2d 505, 509, 512 (2d Cir. 1977) (securities law).
Wigmore § 1949, at 66.
See also EXPERTS.{/footnote}

DA-DE Exceprts

DANGEROUSNESS