David Kelley first pointed out to Mathews the probable existance of a ruler at Palenque with the name Pacal . This ruler is Kubler's "Sun Shield" and Berlin's "Subject A". His principal name is the T624 a or b 'shield' glyph. Frequently his name glyph is accompanied by a complementary glyph group (T586 or 602 or 1014'd' or 1023 or :25 or 205:178) which should be read as 'pa-ca-l(a) '. David Kelley has proven that the pa-ca-l(a)  reading beyond any reasonable doubt. It is, however, appropriate to discuss here the variant forms of the glyphs which are read as pa  and ca  (figure 2).