A teacher shall retain but not accrue seniority if the teacher is:
a) on leave of absence in excess of thirty (30) calendar days;
b) laid off for a period of time less than that set out in subsection 19.11 c) hereof;
c) absent because of illness or accident for more than the maximum number of days accumulated under the provisions of the collective agreement;
d) absent because the Division has granted more maternity leave than required by the Employment Standards Code (C.C.S.M. - E-110).