The following summaries are a handout I prepared for lectures in the late 1970s, about the same time Interpreting Solar Returns was written. Its purpose is to give concise keys to the differentiated natures of a transiting vs. natal planet being foreground in a return.
While I might revise these a tiny bit now, the core ideas are solid. These were written to be equally true whether the planets are foreground in a Solar Return or a Lunar Return. However, there is a distinction: A planet conjunct an angle of a Solar Return also has a quality of being conjunct the Sun - and the interpretations in Interpreting Solar Returns were written with this in mind. Similarly, a planet conjunct an angle of a Lunar Return also has a quality of being conjunct the Moon - which is how I would have written the different "angular planet" interpretations if I'd finished the planned companion volume, Interpreting Lunar Returns.
For that matter, this principle is true for any type of planetary return. Thus, the meanings below are essentially what they would be in any kind of return chart except, for instance, a planet angular in a Mars Return would have the additional characteristics of acting as if conjunct Mars.
These summaries may also provide the basic "inside vs. outside" ideas for understanding how transit interpretations are derived.
r. SUN: Identity is brought under consideration. Assertiveness, direction. Pride, authority, desire for recognition. Vitality.
t. SUN: Receiving special attention. Encounters with "authorities." Honor, achievement, recognition.
r. MOON: Strongly responsive to astrological and environmental stimuli. Receptive, impressionable, vulnerable, sensitive. Indiscriminate reactions (care-free, juvenile). "Nesting" behavior.
t. MOON: Hyper-reactive (and vulnerable) to environment. Surrounded by emotional excitement, rapid and excessive motion, unstable conditions and change. Appetites easily aroused. Popular attention.
r. MERCURY: Exchange of data. Curiosity, learning, discussions. Data storage/processing/retrieval. Commercial, analytic, busy.
t. MERCURY: Transportation and communication themes. Self-expression. Busy-ness and business.
r. VENUS: Expressing love. Beauty and harmony important (vanity). Deep feelings roused. Pair-bonds formed or maintained.
t. VENUS: Affection received. Relationships are a central issue. Surroundings pleasant, harmonious, soft.
r. MARS: One is aggressive, competitive, physically expressive, assertive, irritating, willful, sexually adamant.
t. MARS: Aggression received. Atmosphere tense, heated, irritating, confronting. Presence of competition, energy, assertion, drive. Injuries, physical discomfort. Sexual bounty.
r. JUPITER: Self-esteem, confidence, feeling lucky, happiness. Desire for expansion/improvement/self-elevation. Amiable, tolerant, congenial, generous (extravagant).
t. JUPITER: Fortune coming from without. Esteem, respect, recognition, honors, material gain, elevation, gifts, advantage, opportunities, luck.
r. SATURN: Emphasis on own demands and (self-)expectations (self-doubt, sense of own inadequacies, poor health, depression). Survival behavior: feelings in check; selfish, tenacious, security-minded. Space- and time-sensitive (territorial).
t. SATURN: Demands coming from without. Daily survival needs emphasized (shortage). Restriction, delay, frustration, separation. Tasks accumulate. Others have no sympathy, seem critical.
r. URANUS: Desire for freedom, novelty, excitement, discovery (feeling stifled). Clarity of outlook. Emancipatory, rebellious, claiming independence. Risking, enthusiastic, less inhibited.
t. URANUS: Freedom, openness. Changes originating from without. Excitement (tension). Sudden new direction, surprise. Travel, adventure, renewal. Progressive, stimulating. Discovery.
r. NEPTUNE: Absorption in or by something. Exaggerated responses (vulnerable, embarrassment, anxiety). Physical/emotional sensitivity, idealism (easily frustrated; self-doubt). Imagination (selective perception, confusion). "Avoidance" behavior.
t. NEPTUNE: Exaggerated state of emotional excitement. Temptation, seduction (pleasure-oriented; impressionable). Dependency, victimization, altered reality. Efforts diluted, frustration, "avoidance" behavior. Drama, music, fantasy, mysticism, etc.
r. PLUTO: Separation, isolation. Retreat or withdrawal from world. Escape from demands and pressures. Confrontive introspection and re-evaluation. Culminations - decisions are forced.
t. PLUTO: Separative, isolating ("singles out from the herd"). Dramatic interruptions, alterations, and transformations. Need for adjustment. Climactic, intensive, sensational events. Crisis, shock. Life revolts against expectancy.