"informally called" is a grammatically correct phrase that can be used in formal and informal contexts.
For example, "The Grand Canyon is informally called the 'Eighth Wonder of the World'."
Some Native Americans live on tribal landholdings that are informally called reservations.
Some Chickasaw now live on tribal landholdings that are informally called reservations.
These were jawless, armored fish informally called ostracoderms, but more correctly placed in the taxon Pteraspidomorphi.
Informally called the Blackwood, the truck might be based on the big Ford Super Duty.
They were informally called deputy prime ministers, making it clear who was to take over".
Turkers, as the independent contractors are informally called, choose a task they like and are qualified for.
Because of its 20 Art Deco-style buildings, the area was informally called Hollywood Flats when it was first created.
Choristoderes, sometimes informally called champsosaurs, are a clade of semiaquatic diapsids with an extremely long stratigraphic range.
That building, still informally called the Banespão, was completed in 1947, and was for a while the tallest in Brazil.
The newest worry for local botanists is a native of Asia informally called mile-a-minute weed.
INSIDE the "War Room," as it is informally called, Israeli soldiers gaze at banks of computer and television screens.
