Visual layouts vary by language, country, and user preference, and the same mechanical layout can be produced with a number of different visual layouts.

They can sometimes be changed by different programs or by user preference.

Mobility canes are often made from aluminium, graphite-reinforced plastic or other fibre-reinforced plastic, and can come with a wide variety of tips depending upon user preference.

Several methods were proposed by researchers to speed up convergence, like interactive constrain evolutionary search (user intervention) or fitting user preferences using a convex function.

Stored data and user preferences enable roaming users to access applications and data as if they were using their own desktop machine.