Which two types of users can airports reasonably distinguish between?

Airports can effectively distinguish between signatory and non-signatory carriers based on their agreements with the airport authority. Signatory carriers typically have lease agreements that outline their rights and responsibilities at the airport, including gate assignments and fees, often reflecting a long-term operational presence. These carriers are usually major airlines, domestic and international, that commit to a stable level of operations at the airport.

Non-signatory carriers, on the other hand, may operate at the airport but do not have such formal agreements. These could include charter airlines, low-cost carriers, or other operators who use the airport on a more ad hoc basis without the same level of commitment or operational integration as signatory carriers. This distinction is important for airport management and planning, as it affects revenue generation, service guarantees, and resource allocation.

The other options do mention types of carriers, but they do not align as closely with the operational agreements and distinctions that airports prioritize in their management practices. For instance, while major and local airlines can be compared, this doesn't delve into the structural distinctions like those found between signatory and non-signatory carriers. Similarly, charter versus freight carriers and private jets versus commercial airlines do not consistently reflect the contractual relationships that airports utilize to differentiate user types.