Providing service layer credits is a great way to communicate data sources, however there should be an easier way to opt out (or opt in) instead of hitting Insert > Dynamic Text> Service Layer Credits and removing the text box from the data frame. A lot of projects require high level maps with very specific formatting and information and the service layer credits (typically referring to ESRI basemap services) need to be removed for these documents. In past projects, to reference ESRI (and other data sources) we have used small logos representing the companies, which takes up much less space and fits the map format. Perhaps the service layer credits could be a setting in ArcMap Option instead?