Below are the Guidelines of the American Chemical Society (ACS) - my interpretation being, if a person has any financial ties with any institution at the time of submission, they are required to disclose the names of entities with whom such ties exists, and also state if those ties represent any conflict with the work being submitted, or if there is no conflict. If no financial ties exist at the time of submission, it does not need to be included. IMO.
EDIT: For the specific $PPHM abstract that will be posted this afternoon, as you can see the scientists that are employees of companies only have the specific company listed, whereas the two scientists who are with different cancer centers have multiple listings, main from the fact that they may be associated with several clinical trials that have not yet been completed - as we know trials can take a long time from recruitment stop to completion. There could be other consulting arrangements in there also, of course.