Modes

These are the 3 modes we use for filtering the lists of available words to guess from:
Standard	As in standard mode Wordle play, all possible words remain available as valid guesses. There is no requirement to stick to the green and yellow tiles exposed by the earlier guesses. Grey tiles can be reused even though these letters are known not to be part of the solution.
Hard *	As in hard mode Wordle play, all greens tiles must be matched and all yellows must be in the next guess. Yellow tiles can be in any position (except those taken by a green). That includes re-use in the position that arose to the yellow tile. Grey tiles can be reused even though these letters are known not to be part of the solution.
Strict **	This is the equivalent of the filtering that is actually applied to the solutions (or full word list) to get the remaining words available. While this is not a Wordle mode, this is the way in which we try to play the games. All green tiles must be matched in the subsequent guesses. All yellow tiles must be in the subsequent guesses (and may not be in the same position). No grey tiles can be reused in subsequent guesses.
Note:	When solving in hard and standard modes, Solver uses a slight variation to their definitions above. When solving in these modes, no grey tiles can be reused in subsequent guesses. This reduces the work that Solver has to do without significantly reducing its options.