Art. 8 CISG
(1) For the purposes of this Convention statements made by and other conduct of a party are to be interpreted according to his intent where the other party knew or could not have been unaware what that intent was.
(2) If the preceding paragraph is not applicable, statements made by and other conduct of a party are to be interpreted according to the understanding that a reasonable person of the same kind as the other party would have had in the same circumstances.
(3) In determining the intent of a party or the understanding a reasonable person would have had, due consideration is to be given to all relevant circumstances of the case including the negotiations, any practices which the parties have established between themselves, usages and any subsequent conduct of the parties.
The Secretariat Commentary on Art. 7 of the 1978 New York Draft, predecessor to Art. 8 CISG, gives insight into the drafters' unterstanding on the eve of the 1980 Vienna Diplomatic Conference.
CISG-AC Opinion regarding Art. 8 CISG
CISG-AC Opinion No. 3 ‘Parol Evidence Rule, Plain Meaning Rule, Contractual Merger Clause and the CISG’ (Rapporteur: Richard Hyland), adopted by the CISG Advisory Council at its 7th meeting in Madrid (Spain) on 23 October 2004
Overview of case law on Art. 8 CISG: UNCITRAL Digest
The UNCITRAL Digest on the CISG can be used as a starting point to discover the relevant case law on this article.