+ XM <EM>string</EM>, override <EM>ncurses</EM>'s built-in string which enables/disables
+ <STRONG>xterm(1)</STRONG> mouse mode.
+
+ <EM>ncurses</EM> sends a character sequence to the terminal to initialize
+ mouse mode, and when the user clicks the mouse buttons or (in
+ certain modes) moves the mouse, handles the characters sent back
+ by the terminal to tell it what was done with the mouse.
+
+ The mouse protocol is enabled when the <EM>mask</EM> passed in the
+ <STRONG>mousemask</STRONG> function is nonzero. By default, <EM>ncurses</EM> handles the
+ responses for the X11 xterm mouse protocol. It also knows about
+ the <EM>SGR</EM> <EM>1006</EM> xterm mouse protocol, but must to be told to look
+ for this specifically. It will not be able to guess which mode
+ is used, because the responses are enough alike that only
+ confusion would result.
+
+ The <STRONG>XM</STRONG> capability has a single parameter. If nonzero, the mouse
+ protocol should be enabled. If zero, the mouse protocol should
+ be disabled. <EM>ncurses</EM> inspects this capability if it is present,
+ to see whether the 1006 protocol is used. If so, it expects the
+ responses to use the <EM>SGR</EM> <EM>1006</EM> xterm mouse protocol.
+
+ The xterm mouse protocol is used by other terminal emulators.
+ The terminal database uses building-blocks for the various xterm
+ mouse protocols which can be used in customized terminal
+ descriptions.
+
+ The terminal database building blocks for this mouse feature also
+ have an experimental capability <EM>xm</EM>. The "xm" capability
+ describes the mouse response. Currently there is no interpreter
+ which would use this information to make the mouse support
+ completely data-driven.
+
+ <EM>xm</EM> shows the format of the mouse responses. In this experimental
+ capability, the parameters are
+
+ <EM>p1</EM> y-ordinate