I found some information in the EnergyPlus documentation. First, there is the Plant Coincident Sizing Algorithm:

A special report is issued to the eio file that provides details for the Coincident sizing option. Coincident plant sizing adjustments using HVAC Sizing Simulations run a sizing algorithm at the end of each Sizing Pass. The following report provides details on the calculations and observations from monitoring the previous Sizing Pass.

And then more specifically, the Input Field Description:

This field shows the field description/variable with units. When using HVAC Sizing Simulation for advanced sizing methods, there are two versions of the report for each component that might be affected. With HVAC Sizing Simulation, there is a first size value reported, which is the result of the Ideal Loads Sizing Simulation, and there is the final value after all the Sizing Passes have completed. This input field description will have “Initial” prepended to the description to indicate that this is the first size, the same report without “Initial” is the final size. Note that with HVAC Sizing Simulation, these reports will occur much later in the simulation and hence appear further down in the .eio file.

This is documentation for the EIO output file but surely applies to the html outputs too.