  We define formal orbifolds over an algebraically closed field of arbitrary
characteristic as curves together with some branch data. Their \'etale
coverings and their fundamental groups are also defined. These fundamental
group approximates the fundamental group of an appropriate affine curve. We
also define vector bundles on these objects and the category of orbifold
bundles on any smooth projective curve. Analogues of various statement about
vector bundles which are true in characteristic zero are proved. Some of these
are positive characteristic avatar of notions which appear in the second
author's work ([Par]) in characteristic zero.
