The data file crXXXX.dat was written using the following Fortran statements:

100   format (i5)
103   format (12f10.3)
104   format (12f10.4)
105   format (12f10.5)

          write (*,100)  ncarr
          write (*,100)  long
          write (*,105)  ((bss(i,j),i=1,72),j=1,37)
          write (*,103)  ((fexp(i,j),i=1,72),j=1,37)
          write (*,104)  ((theta(i,j),i=1,72),j=1,37)
          write (*,104)  ((phi(i,j),i=1,72),j=1,37)
          write (*,105)  ((bphot(i,j),i=1,72),j=1,36)

Here, ncarr and long are the Carrington rotation number and longitude of the leading (i.e.,eastern most) edge of the 360 degree map,
bss is the source-surface field in Gauss,
fexp is the flux-tube expansion factor evaluated at the source surface,
theta (colatitude in radians) and phi (longitude in radians) give the photospheric footpoint coordinates of the source-surface (i.e., open) field lines.

The potential-field source-surface model with radial photospheric boundary condition and source surface R_ss = 2.5 R_Sun was used (for a description of the model, see Wang & Sheeley, 1992, ApJ, 392, 310).  The index i corresponds to every 5 deg of longitude (i.e., 2.5 deg, 7.5 deg, ..., 357.5 deg) at the source surface.  The index j corresponds to every 5 deg of latitude (i.e., -87.5 deg, -82.5 deg, ..., +87.5 deg) at the source surface.
The 37th j value corresponds to the latitude of the ecliptic.
Finally, bphot gives the photospheric field in Gauss for every 5 deg of longitude and latitude at the photosphere.