Linked from
The 14 pages that link to Perchloric acid, each with the reason it gives.
OxoacidBroader topic: It is a chlorine oxoacid whose conjugate base is perchlorate.
PerchlorateCompared with: The acid is the protonated counterpart of the perchlorate anion.
Chlorous acidCompared with: It is the most oxygen-rich member of the common chlorine oxoacid series.
Bromic acidCompared with: It contrasts a highly oxidized halogen acid with bromic acid’s +5 state.
Iodic acidCompared with: Its central halogen reaches +7 rather than iodic acid’s +5.