Uncertainty in the GNOME user manual

Hi all,

while translating the user manual, I stumbled upon two strings which I
cannot retrace in the current GUI (print dialog):

#. (itstool) path: item/p
#: C/printing-booklet-singlesided.page:70
msgid ""
"Under <gui>Page Sides</gui>, in the <gui>Include</gui> drop-down list, "
"select <gui>Front sides / right pages</gui>."
msgstr ""

#. (itstool) path: item/p
#: C/printing-booklet-singlesided.page:87
msgid ""
"Under <gui>Page Sides</gui>, in the <gui>Include</gui> drop-down list, "
"select <gui>Back sides / left pages</gui>."
msgstr ""

I can't find any corresponding workflow which relates to these
strings. Maybe this feature has changed or is no longer available...?
In any case, it needs some clarification. Thanks in advance for your
help.

Best Regards,
Mario