Order of the main sections (<divetrip> shifted) altered:

<divetrip> had to be placed behind <profiledata>, to allow cross-referencing within <divetrip> to dives stored inside <profiledata> in the <repetitiongroup> sections. In previous versions of UDDF cross-referencing falsely took place to elements so far not defined.

<address> : Can now be given also inside <geography>; additionally, the element <province> (previously a child element of <geography>) is moved here.

<country> : Removed as child element of <geography>, because <address> contains it which now can be given inside <geography> (see above).

<divebase> : attribute id added

<passedtime>

<surfaceinterval>

<depth> : for the sake of greater flexibility (among other things later on extensions) all attributs introduced in version 2.1.0 were removed, and instead the element <waypoint> is introduced, inside which now <depth>, and the former attributes (<alarm>, <cns>, <divetime>, <otu>, <switchmix/>, and <temperature>) are found as standalone elements.

In all explicitly specified date statements (<birthdate>, <enddate>, <issuedate>, <setdcdate>, <startdate>, <validdate>) no longer the year, month, day, and day of week elements are given but put into brackets via <date>. This standardizes and simplifies date statements.

In all explicitly specified time statements (<setdctime>, <setdcalarmtime>) no longer the hour, and minute elements are given but put into brackets via <time>. This standardizes and simplifies time statements.

<text> — it is no longer possible to simply insert text, but it must be put into brackets using <para>. See also <notes>.

<mixchangeascent> → <mixchange>

<inputprofiledescent> → <inputprofile>

<pend> → <tankpressureend>

<preserve> → <tankpressurereserve>

<pstart> → <tankpressurebegin>

<pfill> — now <tankpressurebegin> takes on this functionality

<setdcdecomodelname> — now <name> takes on this functionality, too

<students> — now see the element <student/> inside the <buddy> section

<alarm> (see <waypoint>)

<ascent> (see <mixchange>)

<averagevisibility> (see also <sitedata>)

<cns> (see <waypoint>)

<descent> (see <mixchange>)

<diveduration> (see also <setdcdivetimealarm>)

<divetime> (see <waypoint>)

<equipmentused> (inside <dive>)

<maximumvisibility> (see also <sitedata>)

<minimumvisibility> (see also <sitedata>)

<otu> (see <waypoint>)

<setdcdecomodel>

<setpo2> (see <waypoint>)

<student/> (see also <buddy>)

<switchmix/> (see <waypoint>)

<temperature> (see <waypoint>)

<tripmembership> (see <dive>)

<waypoint>

All cross-referencing elements are now explicitly listed: