Halliday & Matthiessen (2014: 383):
In an incongruent nominal group corresponding to a congruent clause, Qualifiers correspond to participants or circumstances in the transitivity structure of the clause; or when the Head/Thing of the nominal group is a nominalisation of a verb of sensing or saying, they may correspond to projected clauses in a clause nexus.Carnation has been available in the UK since 1946, but the main marketing effort dates only from 1954 with the removal [of restrictions [on sales] ].
THE decision [by the Arbitration Commission] [[ to award the 2.3 percent pay increase]] is unfortunate, but it was to be expected.
This is the real meaning of the US Senate’s decision [last week] [[ to override any possibility of a presidential veto for real, hard-hitting sanctions against the separate, increasingly desperate tribes [[ that make up the political entity of South Africa]] ]] .
As the examples illustrate, participants reconstrued as Qualifiers are realised by prepositional phrases with either of or by; circumstances are realised in the same way that they would be realised in clauses, by either prepositional phrases or adverbial groups.