The set title command produces a plot title that is centered at the top of the plot. Using the optional x,y screen offsets, the title can be placed anywhere on the plot. set title with no parameters clears the title.
Syntax:
set title {"<title-text>"} {<xoff>}{,<yoff>}
show title
Specifying constants <xoff> or <yoff> as optional offsets for the title will move the title <xoff> or <yoff> character screen coordinates. Note these are screen coordinates and not plot coordinates. For example,
set title ,-1
will change only the y offset of the title, moving the title down by roughly the height of one character.
(The EEPIC, Imagen, LaTeX, and TPIC drivers allow 
in a string to specify
a newline.)