puhekieltä A card sent out by a travelling dance or theatre company to request temporary personnel from a local labor union.
1991, M. Kay Barrell, The technical production handbook
Some large modern dance companies, most large ballet companies, and most large theater companies also require union crews. These are called yellow card companies.
2014, John Ramsey Holloway, Illustrated Theatre Production Guide (page 6)
Each local union has a separate number; New York was the first so they are Local One. Chicago is Local Two. A yellow card (they have been printed on yellow cardstock since time began) is sent out telling how many hands will be required in in each department for the load-in, load-out, and for the run of the show.