The letter sometimes is printed without the diaeresis as ‘o’.
diaeresis or synaeresis may usually be employed according to the case.
With regard to modulation, too, the lines with diaeresis differ from those without it.
With the removal of the hyphenation, these have been changed to use the diaeresis everywhere.
The ending of a word and foot together within the verse is called a diaeresis.
dieresis di·er·e·sis (dī-ěr'ĭ-sĭs)
See solution of continuity.