Places/people/things:

• DhO: the Dharma Overground (this forum)
  
• IMS: Insight Meditation Society, vipassana retreat centre in Massachusetts, USA
  
• KFD: Kenneth Folk Dharma, pragmatic dharma forum emphasising Kenneth Folk's 'Three Gear Transmission' approach. Also Kenneth's personal website

Vipassana-related:

• 1st Path/2nd Path/3rd Path/4th Path: Usually refer to attainments as described in MCTB here.
  
• 3Cs: the Three Characteristics, also the insight stage
  
• 4NTs: the Four Noble Truths [1] [2]
  
• A&P: The Arising & Passing Away (insight stage) [1] [2]
  
• DO - Dependent Origination [1] [2 (pdf)]
  
• DN: the Dark Night (the insight stages)
  
• EQ: Equanimity (the insight stage)
  
• MCTB: Mastering the Core Teachings of the Buddha, Daniel Ingram's book
  
• MCTB 2: Working title for project to update and expand on MCTB with assistance of DhO members. Also called 'Remastering the Core Teachings of the Buddha'
  
• NS: Nirodha Samapatti, 'The Cessation of Perception and Feeling' (temporary attainment) [1] [2]
  
• SE: Stream Entry (aka 1st Path)[1] [2] [3]

Other types of meditation:

• 6Rs: Technique taught at dhammasukha.org: Recognize, Release, Relax, Re-smile, Return, Repeat
  
• MBSR: Mindfulness-Based Stress Reduction
  
• TM: Transcendental Meditation

Actualism-related:

• AF: Actual Freedom [1] [2] [3]
  
• AFT: the Actual Freedom Trust, usually used to refer to the Actual Freedom Trust website
  
• EE: Excellence Experience
  
• HAIETMOBA : How Am I Experiencing This Moment Of Being Alive ("Note: asking how one is experiencing this moment of being alive is not the actualism method; consistently enjoying and appreciating this moment of being alive is what the actualism method is")
  
• PCE: Pure Consciousness Experience [1] [2] [3]
  
• VF: Virtual Freedom