The figure below was obtained in Word using the Arial font. They show, first the LATIN SMALL LETTER A (0061) progressively combined with the diacritics COMBINING ACUTE ACCENT (0301), COMBINING TILDE (0303) and COMBINING OVERLINE (0305). When I try the same combination with the GREEK SMALL LETTER ALPHA (03B1), one can see that the COMBINING ACUTE ACCENT is placed normally on top and at the center of the character α. But afterwards the diacritics are displaced to the right and upwards. Why does the Arial font do this ? What is the purpose of these displacements ?