The phrase "a custom whereby" is correct and usable in written English.
It can be used to describe a specific practice or tradition that is followed in a particular context or situation.
Example: "In many cultures, there is a custom whereby families gather for a meal during the holidays."
Alternatives: "a tradition in which" or "a practice that involves".
One means is via the harambee, a Kenyan custom whereby people gather to donate money to community projects.
Clinton's regular response to an errant drive is to groan "Oh, no!" The preferred technique, as any good golfer knows, is to whomp the clubhead on the ground and yell "Son of a bitch!" or "Oh, shit!" Clinton has not been shy, though, about availing himself of the mulligan--that golfing custom whereby a player unhappy with his first shot grants himself a second, with no penalty.
Not the least remarkable discovery was that of the custom whereby kings were buried along with a whole retinue of their court officials, servants, and women, privileged to continue their service in the next world.
On the surface, the crowdfunding website Kickstarter, Indianapolis Colts coach Chuck Pagano, and Fukubukuro a Japanese New Year's custom whereby merchants sell grab bags of goods—seem completely unrelated.
She was his only queen in defiance of custom, whereby the king had several wives, and many concubines and seems to have been a Burmese Lady Macbeth.
She was his only queen — in defiance of custom, whereby the king had several wives, and many concubines — and seems to have been a Burmese Lady Macbeth.
Cps loci were identified and extracted from the assemblies using a custom Python script, whereby BLAST was used to identify sequence regions with homology to the flanking genes galF and ugd (nucleotide BLAST followed by protein BLAST if no nucleotide-level matches were found).
A work sampling observation approach within each 60 minute block whereby a custom software program presented still images to observers selected according to a 55-second interval approach.
A custom developed early in the history of Himalayan climbing whereby, to avoid confusion, different nations in general took on different peaks.
A custom game is the output of the process part as shown in Figure 1, whereby the game is ready to be played by the patient.
