baby pilots with a white card had to add ISTR 300ft.
... and infant UAS pilots with “Budgie” wings and a PIFG (preliminary instrument flying grading) had even more restrictive limits. However, the limits were theoretical, since we were never sent solo in anything approaching IMC. The closest I came to using my IF skills in anger, was at Lindholme, where the weather suddenly deteriorated and all the Chipmunks were recalled. I remember being Number Five downwind, with a rapidly lowering cloud base.