A sentence, S, can either describe itself, or not.
If it does not, we could replace it with a sentence that does describe S,
but this might falsify the new description.
Iterating, one of three things could happen:
convergence: a sentence eventually describes itself, stop.
cycling: sn describes sn-1,
..., describes s1,
describes sn, for n>1.
divergence: neither of the above.
Change the sentence in the HTML FORM and
try to exhibit the various forms of possible behaviour.
These books discuss self reference in sentences (and many other things):
D. R. Hofstadter & D. C. Dennett.
The Mind's I.
D. R. Hofstadter.
Metamagical Themas: Questing for the Essence of Mind and Pattern.