• AccurateRip
• Acoustid
• AES/EBU
• AirPlay
• Amplifier
• aptX
• Audio file formats
• • AAC
  • AIFF
  • ALAC
  • APE
  • DSD
  • DXD
  • FLAC
  • MP3
  • MQA
  • M4A
  • WAV
  • WMAL
• ASRC
• AVB
• Bit perfect jitter
• Bits: 16 or 24
• Bit perfect playback
• Bitrate
• Bluetooth
• Burn-in
• BWF
• Cables
  • Analog
  • Speaker
  • Bi-wiring
  • Digital
• CDtext
• Chromecast
• Clipping
• Clock
• Codec
• Compression
• CRC
• Crossover
• Cue sheet
• DAC
• Damping
• DASH
• Digital
• Digital Room Correction
• Dither
• DLNA
• Drivers
  • ASIO
  • Direct Sound
  • Kernel Streaming
  • WASAPI
  • Wave Out
• DoP
• DSP
• EBU R128 (loudness)
• FFT
• FireWire
• Freedb
• Gapless playback
• Generation loss
• HDMI
• Headphone listening
• Hearing
  • Single-sided deafness
  • Hard of hearing
• Hires recording
• Homeplug
• I2S
• ID3
• Inter sample peak
• LDAC
• Linearity (DAC)
• Memory playback
• Music Server
• OCF
• OFC
• PCM
• Perception
• RAID
• ReplayGain
• Ripping
• RFI
• RIAA
• Router
• Sampling, up and over
• Sample Rate Conversion
• Speakers
  • Driver design
  • Crossover
  • Amplification
  • Connecting
  • Measurement
  • Placement
• S/PDIF
• Storage
• Sync
• Tagging
• Toslink
• Transcoding
• UAA
• Units
• UPnP
• USB
• VST
• WiFi
• WiSA

OCF

This stands for Open Connectivity Foundation.

OCF's Mission is Twofold:

1. Provide specifications, code and a certification program to enable manufacturers to bring OCF Certified products to the market that can interoperate with current IoT devices and legacy systems.
2. Make the end user’s experience better by seamlessly bridging to other ecosystems within a user’s smart home and ensure interoperability with OCF compliant devices.

This reminds me of the former DLNA organisation.
However this is about the IoT, the Internet of Things so the scope is much bigger than streaming AV only.
However, part of OFC is certification for UPnP, the original streaming AV-standard.