Insert Key

The Insert key (often abbreviated Ins) is a key commonly found on computer keyboards.

It is primarily used to switch between the two text-entering modes on a personal computer (PC) or word processor:

The insert/overtype mode toggling is not global for the computer or even for a single application but rather local to the text input window in which the Insert key was pressed.

On early text-based computing environments and terminals, when the cursor was in overtype mode, it was represented as a block that surrounded the entire letter to be overstruck; when in insert mode, the cursor consisted of the vertical bar that is highly common among modern applications, or a blinking underline under the position where a new character would be inserted.

Overtype mode can also be referred to as over script mode, and is sometimes erroneously referred to as overstrike mode, which is a typography term.

Notably, on some recent keyboards, the Insert key is completely absent (except on the numeric keypad), its space instead filled with a double-size Delete key.

When keymapping using Octal code, set the desired key by sending \e\161 to perform the "insert" function.

Modern word processing applications operate in insert mode by default, but can still be switched to overtype mode by pressing the Insert key. However, the cursor generally does not change into the letter-surrounding box seen on old text-based systems. Instead, an "OVR" indicator on the status bar is highlighted. This is difficult to notice, so other text editors retain the original cursor change in addition to the indicator.

The Insert key, when pressed along with Control or Shift, can also be used to copy or paste in Microsoft Windows. This behavior comes from the Common User Access standard.

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