What's That Flat?
Deletion
A word or phrase becomes another when an interior letter is removed.
simile sLepanto LeDELETION (*7, 4-2)
We found a TWO for shelter from the sun-
So unrelenting was the summer heat-
And looked out at the sparkling Gulf of ONE,
Where long ago the Turks had met defeat.=Mangie
A deletion may include more than two words.
startling  startling  
starling  starling  
staring  staring  
string  string  
sting  sting  sing  
(Do you want to go on to THREE = sin and TWO = in? In NPL terms, those are not deletions but one curtailment and one beheadment. You could still use all eight words in one puzzle, but you’d have to warn the solver that two-unspecified-steps were a curtailment and beheadment, not deletions.)
Baltimore deletion
Each letter in turn is removed to form a new word.
peat  peat  eat  
peat  peat  pat  
peat  peat  pet  
peat  peat  pea  
Bigram deletion
A word or phrase becomes another when two consecutive interior letters are removed.
catenary caRepeated-letter deletion
A word or phrase becomes another when one letter is removed wherever it occurs.
bassist  bassist  bait  
prospered  prospered  rose-red  
Reversed deletion
After you’ve deleted a letter from the first word, you reverse it to get the second.
espalier espalPhonetic deletion
A word or phrase becomes another when an interior sound is removed.
revelry revelFor discussion of what constitutes a single sound, see phonetic flats.
More Examples
All sorts of combinations of these elements are possible.