I added a test to SVGscan to look for xlink:href links to external URIs. In
release 0.17 it finds 130 of these, in 80 different files. Most of them seem to
be links to bitmap images on the author's hard disk. In some cases this is the
only graphical content of the SVG file, which is therefore effectively empty and
can be deleted. In other cases the bitmap image appears to be inconsequential,
and it will suffice to remove the link to it. There are probably also some
intermediate cases.

The 80 files are listed below.

animals/birds/cormorant-md.svg
animals/birds/duck_yellow_ii_kurt_cagl_.svg
animals/bugs/ant.svg
animals/bugs/spider.svg
computer/building_zazou.svg
computer/classic_phone_zazou.svg
computer/computer_zazou.svg
computer/ebuild_andy_fitzsimon_r.svg
computer/icons/LyX.svg
computer/icons/apacheconf..svg
computer/icons/apacheconf.svg
computer/icons/blender.svg
computer/icons/ebuild_andy_fitzsimon_r.svg
computer/icons/etiquette-theme/apps/LyX.svg
computer/icons/etiquette-theme/apps/apacheconf..svg
computer/icons/etiquette-theme/apps/apacheconf.svg
computer/icons/etiquette-theme/apps/blender.svg
computer/icons/etiquette-theme/apps/firefox.svg
computer/icons/etiquette-theme/apps/gimp.svg
computer/icons/etiquette-theme/apps/gnome-graphics.svg
computer/icons/etiquette-theme/apps/wine.svg
computer/icons/etiquette-theme/blender.svg
computer/icons/etiquette-theme/gnome-compressed.svg
computer/icons/etiquette-theme/gnome-graphics.svg
computer/icons/etiquette-theme/gnome-mime-application-x-deb.svg
computer/icons/etiquette-theme/gnome-mime-application-x-rpm.svg
computer/icons/etiquette-theme/mimetypes/gnome-compressed.svg
computer/icons/etiquette-theme/mimetypes/gnome-mime-application-x-deb.svg
computer/icons/etiquette-theme/mimetypes/gnome-mime-application-x-rpm.svg
computer/icons/etiquette-theme/stock/4wd.svg
computer/icons/etiquette-theme/stock/ant.svg
computer/icons/etiquette-theme/stock/rollerblades.svg
computer/icons/etiquette-theme/stock/spider.svg
computer/icons/firefox.svg
computer/icons/gimp.svg
computer/icons/gnome-compressed.svg
computer/icons/gnome-graphics.svg
computer/icons/gnome-mime-application-x-deb.svg
computer/icons/gnome-mime-application-x-rpm.svg
computer/icons/otto_01.svg
computer/icons/plastik_icon_v05.svg
computer/icons/plastik_icon_v06.svg
computer/icons/plastik_icon_v07.svg
computer/icons/plastik_icon_v08.svg
computer/icons/plastik_icon_v11.svg
computer/icons/plastik_icon_v12.svg
computer/icons/plastik_icon_v13.svg
computer/icons/plastik_icon_v14.svg
computer/icons/wine.svg
computer/internet_zazou.svg
computer/munch_student_zazou.svg
computer/network_zazou.svg
computer/residential_house_zazou.svg
computer/router_zazou.svg
computer/satellite_hub_zazou.svg
computer/satellite_zazou.svg
computer/server_zazou.svg
computer/set_top_box_zazou.svg
computer/teacher_zazou.svg
computer/tft_screen_zazou.svg
computer/tv_zazou.svg
education/otto_01.svg
food/beverages/alcohol/wine.svg
food/fruit/bananas_nicu_buculei_01.svg
geography/astronomy/jupiter_dan_gerhards_01.svg
people/fireman_enrique_meza_c_01.svg
recreation/rollerblades.svg
shapes/shadow_babe_robert_seitz_01.svg
signs_and_symbols/clouds_jon_phillips_04.svg
signs_and_symbols/clouds_jon_phillips_05.svg
signs_and_symbols/clouds_jon_phillips_06.svg
signs_and_symbols/flags/america/united_states/usa_northcarolina.svg
signs_and_symbols/flags/eu_flag_hash_0x8a0ab9c__01.svg
signs_and_symbols/flags/signalflag_alpha.svg
signs_and_symbols/flags/signalflag_bravo.svg
tools/magnifying_glass_tom_kra_.svg
transportation/vehicles/4wd.svg
unsorted/grounded.svg
unsorted/waterbg_none1.svg
unsorted/waterbg_none_.svg