The Universal Worklist (UWL) retrieves the user id of the creator of a work item, displayed in "From" field in Universal Worklist Inbox, from the Business workflow. Whether the value has "US" as prefix or not, depends on the application which starts the workflow. Neither UWL nor Business workflow have control on this.
Starting from SAP NetWeaver 7.0 SP10, only valid backend creator id that is mapped to a portal user will be displayed
in "lastname, firstname" style. All other user data, including technical value starting with US, will be suppressed and the
"From" field will be shown empty.
In SAP NetWeaver 7.0 SP11 and above, the "From" field will not be left empty for an invalid unmapped id, but a localized
text "Workflow System" will be displayed.
Refer to a screenshot depicting the above behavior below: