warning-series

warning-series is a variable defined in `warnings.el'.
Its value is

nil

• This variable may be risky if used as a file-local variable.

Documentation:
Non-nil means treat multiple `display-warning' calls as a series.
A marker indicates a position in the warnings buffer
which is the start of the current series; it means that
additional warnings in the same buffer should not move point.
If t, the next warning begins a series (and stores a marker here).
A symbol with a function definition is like t, except
also call that function before the next warning.