Excerpt from my latest Sasstrology post. Comments have been disabled for this post on this site, please leave comments on the Sasstrology site.
"In a previous post, I discussed the significance of the progressed DC (and Ascendant) changing signs. But there are more indicators of changes via the progressed AC/DC, and these involve aspects to your natal planets. The progressed angles into new signs describe an overall shift in how you approach relationships. Aspects to the natal planets (whether the angles have changed signs or not) describe the quality of specific events."