It could mean auditors, for example, who have to visit businesses and who cannot go to these businesses on their premises because of physical distancing rules. It could also be that they are prevented from having too many people in the same workspace, such as on the same floor. Those could be work limitations that could be covered by 699. It's a broad category. These are just a few examples.
On December 2nd, 2020. See this statement in context.