(By Matthew S. Dryer): "This map shows the dominant order of lexical object, oblique phrase and verb. An oblique phrase is a noun phrase or adpositional phrase (prepositional or postpositional) that functions as an adverbial modifier (or “adjunct”) of the verb. Of the six logically possible orders, five are attested...❡
Oblique phrases include phrases expressing location (such as source and goal), instruments (as in (1a)), benefactives (as in (1c)), and comitatives (as in English with Pat in I played tennis with Pat ). Indirect objects (recipients with ditransitive verbs) are not included; in some languages they pattern with the direct object, in others with obliques. Temporal expressions are not included, since in many languages they exhibit positional properties different from other obliques, often occurring at the beginning of the clause."
In the Grammaticon, "oblique" is defined as flagged differently from S-/A-/P-arguments, so recipient nominals are oblique if they are dative-flagged. There are no semantic-role limitations on the notion of "oblique", in contrast to this WALS chapter.