Compare
Compare is not on every collection. Use it only where the page draws the control. There is no compare box on the index.
Companies
After you open a company, you can chart one reported line. Chart type is Line or Bar. Compare to sets that line beside peers. The figures stay as reported. They are not advice and not a live quote.
Elements
Open an element, then pick the property. The chart sets that element against the group the page names. The caption says what the comparison is against. A missing value is not drawn as zero.
Electric vehicles
Open a vehicle, then pick a specification. The page shows how that model sits among the others on that specification. It does not pick a winner.
Commodities
On coffee, Property Selection compares one measured property of the selected species with the others. If Forge does not hold the property, it is not on the chart.
Star systems
Inside a system, you can select a planet that the system records. The comparison is among the bodies on that page, not against a body Forge never stored.
Shared collections
The shared list does not add a compare control of its own. Read two profiles by choosing them one after another in Item Search. Related names on the profile are links to other records, which is Related records, not a comparison chart.