Page Comparison

If (number-of-accepted-IdPs is less than TBD1) then 
{
  Display all of them as a set of icons
} else if (number-of-accepted-IdPs is less thanTBD2) then

{
 Display all of them by name in a vertical list
} else

{
  // there is either a large (i.e. more than TBD2) fixed set of acceptable IdPs
  // or there is an unknowably sized set of acceptable IdPs (e.g. the RP supports WebFinger)
  If (RP supports WebFinger AND RP supports a fixed set of acceptable IdPs) then
   {
    Display a text entry widget whose label says
       "type an email address OR the name of an identity provider)
  } else if (RP supports a fixed set of acceptable IdPs) then 
  {
    Display a text entry widget whose label says "find your identity provider"
  } else if (RP supports WebFinger) then
  {
    Display a text entry widget whose label says "type an email address"
  }
}