[dba-SQLServer]* in field name?

where     bc.carrera=a.carrera
and bc.plan_estud=a.plan_estud
and a.boleta*=k.boleta

=======Ran across what appears to be an unusual syntax -- the use of * in a
field name? Is that what this is? What does this mean or am I
misunderstanding what I'm seeing?

Susan H.