d0cmf (defined from Dušan's "Zero" Caret Matrix Format) is a text format to storing matrix or the data with matrix data (ex. pageviews statistic).
Enconding: More zeros are repleced by char caret and then the count of the zeros, example 0 0 0 → ^3.
1 0 0 0 2 3 0 0 7
1 ^2 0 2 3 ^2 7