Sometimes the line is drawn as low as the baseline, which makes the letter difficult to distinguish from Д.
Since the middle of the 17th century, selection between Ѳ and Ф was re-adjusted to exactly follow the Greek origin, the system still in use in Church Slavonic orthography.
In the first variant of the Petrine Russian alphabet (1707–1708), the letter Ф was eliminated and Fita became the only way to represent /f/.
Many Greek words with Theta were adopted in Russian with Te (Т т) instead of Fita (mostly through Latin or other Western European languages): теорема (theorem), атлетъ (athlete), пантера (panther), фталевый (phthalic), etc.
For example, the Bulgarian, Macedonian and Serbian version of Theodore is Тодор Todor or Теодор Teodor.