easy  && Allows only records with the "Easy" box checked
observed && Only records having an observational entry will appear
messier <> 0
type = "DS" && Only Double Stars
easy and .not. observed && Easy items that have not been seen
substr(object,1,3)="NGC" && Objects beginning with "NGC"
con="Ori" && Only items in Orion
Sky_Atlas = 22 .or. Peter = 14
Norton = 1 .or. Uran = 36
rah > 6 .and. rah < 12 .and. type = "OC"
messier <> 0 .and. .not. easy
decd > 25
type = "VS"
.T. && View all records (same as a blank filter)