Note: Chief warrant officer six was approved by the Army Chief of Staff in 1970 with the anticipation of Congress approving two new grades, W-5 and W-6. However, Congress did not authorize W-5 until 1991 and has still not approved W-6. The original W-5 insignia consisted of a single silver bar superimposed with four equally spaced silver squares with each square bordered in black. In 2004, this insignia was changed to a single silver bar surmounted by a single, narrow, vertical, black stripe, in harmony with the Navy and Marine Corps. The proposed CW6 insignia had two narrow, vertical, parallel, black stripes.