These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.76 s (backtrack: 0/20).

[ebuild  N     ] x11-apps/xprop-1.2.8::gentoo  144 KiB
[ebuild  NS    ] app-text/docbook-xml-dtd-4.3-r2:4.3::gentoo [4.1.2-r7:4.1.2::gentoo, 4.2-r3:4.2::gentoo, 4.4-r3:4.4::gentoo, 4.5-r2:4.5::gentoo] 82 KiB
[ebuild  N     ] app-eselect/eselect-notify-send-0.1::gentoo  0 KiB
[ebuild  N     ] x11-libs/libXScrnSaver-1.2.5::gentoo  USE="-doc" 266 KiB
[ebuild  N     ] x11-libs/libXinerama-1.1.6::gentoo  USE="-doc" 263 KiB
[ebuild  N     ] x11-apps/xset-1.2.6::gentoo  143 KiB
[ebuild  N     ] x11-libs/gdk-pixbuf-2.44.8:2::gentoo  USE="gif jpeg tiff -gtk-doc -introspection -test" 5897 KiB
[ebuild   R    ] app-text/xmlto-0.0.28-r11::gentoo  USE="text* -latex" 125 KiB
[ebuild  N     ] x11-misc/xdg-utils-1.2.1-r11::gentoo  USE="X dbus -doc -gnome -perl -plasma" 287 KiB
[ebuild  N     ] x11-libs/libnotify-0.8.8::gentoo  USE="-gtk-doc -introspection -test" 113 KiB
[ebuild  N     ] x11-misc/dunst-1.13.1::gentoo  USE="X completions dunstify xdg -wayland" 4557 KiB
[ebuild  N     ] virtual/notification-daemon-0::gentoo  USE="-gnome -kde" 0 KiB

Total: 12 packages (10 new, 1 in new slot, 1 reinstall), Size of downloads: 11874 KiB

The following USE changes are necessary to proceed:
 (see "package.use" in the portage(5) man page for more details)
# required by x11-misc/xdg-utils-1.2.1-r11::gentoo
# required by x11-misc/dunst-1.13.1::gentoo[xdg]
# required by virtual/notification-daemon-0::gentoo[-kde,-gnome]
# required by x11-libs/libnotify-0.8.8::gentoo
>=app-text/xmlto-0.0.28-r11 text