with energy composition (in orbit "hot spot") average daily trapped proton flux mission fluence for protons > 25 MeV (or some other cutoff) solar particle event (SPE) proton energy spectrum with fluence per mission peak (worst case) proton flux from SPE with energy composition assumed frequency of occurrence of design case SPE cosmic ray LET spectrum including proton contributions variations on each of the preceding to reflect solar cycle related changes variations on each of the preceding to reflect uncertainties and design margins There are no standardized formats for identifying either the proton environments or the radiation-related requirements for proton effects. The preceding list offers several environment descriptions that are commonly seen in various combinations. Often, the intention is to identify TID levels, a mission-duration proton spectrum for SEE and possibly displacement damage concerns, and a peak flux (or fluxes) for use in assessing peak SEE rates. Item ten in the list touches on the often seen practice of inflating the expected environment to add margin for various reasons, ranging from uncertainties in environment models to part-to-part response non-uniformity and response uncertainty. Margin will be discussed in a later section. In practice, the environments identified in many requirements documents do not always adequately specify the details needed to properly assess proton-related effects. This situation follows, in some part, from a natural lag between the identification of a given important effect (e.g., displacement damage in optocouplers, or proton upset response best described by a two parameter Bendel formalism as discussed later) and the recognition of the need to include detailed proton spectral information rather than just proton-induced rad(Si) and > 25 MeV fluences. Also, the timeline associated with procuring flight hardware may result in periods of years between the definition of the orbit environment description to the detailed design, and new effects, which may emphasize 