I stamped both into the Observation section.
From your continuing (unhindered?) travels to a wide range of countries it can presumably be assumed that it hasn't caused you any problems at "immigration" but - I would have thought that the "Observation" section (Called "Endorsement section" by US) was potentially the more "significant" one in a passport compared with the "Visa" pages.
On a UK passport it states "This page is reserved for official observations". Many of these are of a standard content and format.
"The Observations page is for authorised immigration officials to make notes (observations) that may be useful for other immigration officials to know later. These could include "Deported xx-xx-xxxx for yyyyy reason, zzzzz country" or "Overstayed xx days yyyy country, barred re-entry yyyy until zz-zz-zzzz" Things which would influence entry decisions and which should be seen quickly without flipping through and checking entry/exit dates on every page."!!!!