1) Repeated word in a contract 2) Standard contact legalese 
• (adv.) By which; -- used relatively. • (adv.) By what; how; -- used interrogatively.
Where·by' adverb 1. By which; -- used relatively. 'You take my life when you take the means whereby I life.' Shak. 2. By what; how; -- used interrogatively. « Whereby shall I know this?» Luke i. 18. 
[adv] - as a result of which 2. [adv] - by or through which