This control function moves the cursor forward one column. If the cursor is at the right margin, then all screen data within the margins moves one column to the left. The column shifted past the left margin is lost.
Available in: VT Level 4 mode only
DECFI adds a new column at the right margin, with no visual attributes. DECFI is not affected by the margins. If the cursor is at the right border of the page when the terminal receives DECFI, then the terminal ignores DECFI.