Here we go... note same 'M' in triangular recess of lintel
What the inscription at the entrance of the GreatPyramid, the place of Sunset & Sunrise reads, is: on the left, depicting the two angled causeways of G1 & G2, which from a mutual point of origin, target the Solstice latitude of the Tropics - the glyph of the Globe, on far right portrays that by two parallel lines.
Second from left, the circle with line at centre corrpborates the former inasmuch it being respective of Earth's equator, again emphasised by three parallel lines of latitude...
Astrological use of 'M' symbol / glyph:
One variation depicts the Maiden - the Zodiac constellation of stars, known as Virgo. Intriguingly similar, considering there are only 12 signs, another variation represents the Zodiac constellation of stars, known as Scorpio.