This excerpt taken from the RTRSY 6-K filed Feb 29, 2008.
Deferred Share Units
To further align the interests of Thomson Reuters Directors with those of its shareholders, Thomson Reuters will adopt a share plan for non-management directors (the Thomson Reuters Non-Employee Director Share Plan, as summarised in Section 23.5 of Part XVIII). Under the plan, non-management directors will have the option to receive all or any portion of their annual retainer in DSUs, Thomson Reuters Corporation Shares or Thomson Reuters PLC ordinary shares as determined by the Human Resources Committee. A DSU is a bookkeeping entry credited to an account maintained for each eligible director, and will have the same value as one common share of Thomson Reuters Corporation.