This file gives the (symmetric) covariance matrix, truncated at L=5, in ASCII format. It was created from the binary version "gggrx_0660pm_shb_l50.dat".
Each line gives the matrix elements along each row, with the same parameter ordering as for the "gggrx_0660pm_shb_l50_coefficients.asc" file. 
There are 37 lines/rows/parameters, and the format is "%20.13e " repeated 37 times. Line feed and carriage return characters complete the line (DOS format).