Only this version
When updating from the 2.5 series to the 3 series you may see a large number of warnings and notices on the update page.
This pertains only to Joomla! version(s):- 3.1.0 • 3.1.1 • 3.1.4 • 3.1.5
3.1.2 & 3.1.3 were not officially released
These do not interfere with the update process and may simply be ignored.