PDRY Obligatory Charity Label used from 1977-1978

The label is discussed by Murray Graham in the June 2002 issue of The Dhow. The translation of the label is:

Democratic Yemen
The Eleventh World Festival
of Youth and Students
Five Fils.

The above cover from Mukalla is postmarked 11 December 1977.

The example below from Crater is postmarked 12 February 1978.

I have also seen this cover from Seiyun below postmarked 15 December 1977.