by custom

See: pro forma
References in classic literature ?
It is true, that what is settled by custom, though it be not good, yet at least it is fit; and those things which have long gone together, are, as it were, confederate within themselves; whereas new things piece not so well; but though they help by their utility, yet they trouble by their inconformity.
Color concentrate pellets are supplied for nearly all thermoplastics, either from standard colors in stock or by custom color matching.
The new data analysis and interpretation features provided by Custom APM Services extend and enhance the value of Keynote's benchmarking services and allow Keynote data to be used as vital operational and decision-making tools throughout the organization.
Celebrated by all the members of WCO, International Customs Day is a wonderful reminder of important role played by customs bodies in the world.
Chicago attorney Edward Fox says he represents about 90 African American women--most of whom went through O'Hare--who allege their civil rights were violated by customs agents.
In today's rapidly evolving global trade environment, where countries are more closely scrutinizing cross-border transactions, filing customs forms electronically significantly reduces clearance time as shipping information is received by Customs while a shipment is in-transit to destination.