Some examples of common symbols and signs used by Native American Plains Indians: 

Sitting Bulls Signature 

Meanings of over 50 symbols and signs listed, these can vary based on the specific tribe and context:

1. Arrow - Protection
2. Broken Arrow - Peace
3. Broken Cross Circle - Cycles, Movement, Seasons
4. Interconnected Brothers - Unity, Equality, Loyalty
5. Buffalo Horns - Success
6. Sun - Rebirth
7. Clouds - Change, Transformation
8. Moon - Growth, Creativity
9. Stars - Guidance, Wisdom
10. Teepee - Home, Family
11. Rain - Abundance, Prosperity
12. Thunderbird - Power, Strength
13. Bear - Courage, Healing
14. Eagle - Wisdom, Spirituality
15. Bison - Endurance, Stability
16. Elk - Agility, Independence
17. Horse - Freedom, Journey
18. Antelope - Swiftness, Agility
19. Snake - Regeneration, Adaptability
20. Spider - Creativity, Resourcefulness
21. Geometric Shapes - Balance, Harmony
22. Feathers - Freedom, Spirituality
23. Dream Catchers - Protection, Good Dreams
24. Medicine Wheels - Healing, Balance
25. Animal Tracks - Guidance, Pathfinding
26. Moccasins - Comfort, Protection
27. Tomahawks - Strength, Skill
28. Peace Pipes - Harmony, Unity
29. Quillwork - Artistry, Craftsmanship
30. Beadwork - Beauty, Adornment
31. Leatherwork - Durability, Protection
32. Cliffs - Strength, Protection
33. Caves - Shelter, Sanctuary
34. Lakes - Purification, Reflection
35. Rivers - Renewal, Life Force
36. Waterfalls - Power, Renewal
37. Hills - Perspective, Vision
38. Trees - Wisdom, Growth
39. Forests - Mystery, Spirituality
40. Grasslands - Sustenance, Abundance
41. Deserts - Survival, Resourcefulness
42. Winds - Movement, Change
43. Lightning - Power, Energy
44. Hail - Cleansing, Renewal
45. Snow - Purity, Cleansing
46. Fire - Transformation, Purification
47. Earth - Grounding, Stability
48. Sky - Limitlessness, Spirituality
49. Spirits - Guidance, Protection
50. Ancestors - Wisdom, Connection
51. Elders - Knowledge, Experience
52. Chiefs - Leadership, Authority
53. Warriors - Strength, Courage
54. Healers - Compassion, Service
55. Storytellers - Tradition, History
56. Dreamers - Vision, Inspiration
57. Tricksters - Mischief, Playfulness
58. Shamans - Spirituality, Healing
59. Ceremonies - Celebration, Tradition
60. Dances - Expression, Unity
61. Drums - Rhythm, Communication