A chart can put R beside a retrograde planet. Would the Sun or Moon ever get that mark? In the usual Earth-centred chart, the answer is no.
What the R mark tracks
Retrograde means that a body's position seems to move backward against the background of the sky for a time. Mars can appear to do this when Earth passes it. Its orbit has not turned around.
The Sun and Moon are the exceptions
In the standard chart's Earth-centred view, the Sun follows its apparent yearly path and the Moon moves along its monthly path without making a retrograde turn through the zodiac. So astrologers do not label either one R.
Read the label as a position note
If R is absent beside your Sun or Moon, nothing is missing from the chart. A retrograde label belongs to the chart's way of recording apparent motion. It cannot tell you what will happen or define your character.
A few common questions
Could a changing Moon phase make the Moon retrograde?
No. A phase describes how much of the Moon's sunlit side we see. Retrograde describes a change in apparent direction across the zodiac.
Sources & further reading
Astrology sources describe their own traditions and methods; they do not establish predictive accuracy. The writing exercises are original Lodestar editorial material.
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