Here we list some conventions which are used in this document.

 *  Fortran90 allows generic names which refer to several specific subroutines. Which one of the specific routines is called depends on the type and rank of the arguments supplied in the call. We tag generic names with a * in this document.  
  Nside  HEALPix resolution parameter -- see the HEALPix Primer.  
 map  We use the word ``map'' referring to a function, defined on the set of all HEALPix pixels.  
  $\mathbf{\theta}$  The polar angle or colatitude on the sphere, ranging from 0 at the North Pole to $\pi$ at the South Pole.  
 $\mathbf{\phi}$  The azimuthal angle on the sphere, $\phi\in[0,2\pi[$.  

Version 3.31, 2017-01-06