Could someone point me to a good source to understand Cytobands?

I would like to understand how they have been defined and what do the recognised stain values 'gneg, gpos50, gpos75, gpos25, gpos100, acen, gvar, stalk' mean?

I do know that this is based on the G banding technique and that 'gneg' indicates Giemsa negative while 'gpos' positive ones with increasing intensities of 25, 50, 75 and 100. However I do not know what the other values mean.

Also, does the cytoband profile change with respect to cell type?