Rock Galaxy was a series, much like "Two Originals Of".
David Bowie and Styx both had double compilation albums in this series. It's not really the title of the record but more a group of albums created under the banner "Rock Galaxy" to give people some of the best tracks from the respective artists.
However, the titles of the records in the series of "Two Originals Of" are Two Originals Of Neil Young etc. The same can not be done in the same way in this series.
I agree with (whitewhale1965) The title is wrong for this entry. Also the label should be changed to RCA International.
I have an alternative pressing of this album on the Black RCA label, cat number NL70673 Pressed in Germany for the UK and Europe with an alternative rear cover. I will upload at the weekend.