When astronomical events are reported, there is often a distinction between Notice and Circular: the former is made by machine, the latter by a human. Skyalert brings together these machine and human versions of the truth.
The CRTS stream is generated automatically: the machine looks for sources whose magnitude has brightened by 2 during four exposures 20 minutes apart. The cutouts are generated, lookups made to the Virtual Observatory for how the source looks in other surveys, if it is a known variable, etc. Later, an assessment is made by CRTS staff of what the event might represent, and that is also published into Skyalert. You can see an example here, (scroll to the bottom) where the 13th magnitude transient is identified as the known cataclysmic variable TT Tau.
The same effect happens with the SWIFT alerts, from NASA’s Gamma-ray observatory in orbit, for example here. Scroll to the bottom to see the SWIFT Circulars that explain the meaning of the automated observations.
When viewing a Skyalert event, there can be several different pieces of data shown. Each has in the left margin the four links Overview, Params, XML, None. By clicking these, you can change the representation of that piece of data. Give it a try!