>Небось микрософтово изобретение.

Анафема!

Many keyboards nowadays have two scroll keys labeled `PageUp' and
`PageDown' (or maybe `Prior' and `Next').  If your keyboard has these
keys, you can use them to move forward and backward through the text of
one node, like <SPC> and <BACKSPACE> (or <DEL>).  However, <PAGEUP> and
<PAGEDOWN> keys never scroll beyond the beginning or the end of the
current node.

To move forward through the text and see another screenful, press <SPC>, the Space bar.  To move back up, press the key labeled `Backspace' or `DEL' (on some keyboards, this key might be labeled `Delete').  In a graphical Emacs, you can also use `S-<SPC>' (press and hold the <Shift> key and then press <SPC>) to move backwards, but this does not work in the stand-alone Info reader (nor in Emacs, if you are using it in a text-mode terminal).
  --http://ftp.gnu.org/old-gnu/Manuals/info/html_node/Help--L.html
  --https://www.gnu.org/software/emacs/manual/html_node/info/Hel...