K is for Knowledge Base

I started in the commercial AV industry not that many years ago, and had to start off learning some of the industry's basic knowledge. The industry 's professional organization, Infocomm (no relation, alas, to the computer game company) gives a "Certified Technical Specialist" certification to those who have shown basic knowledge of at leas the language of AV. Later, there are CTS-D (Designer) and -I (installer) designations for those who have achieved a higher level of accomplishment. What occurred to me recently, in that getting the basic CTS required me to know about:

1. Analog video encoding

1. RGBHV
2. RGBS
3. RGsB
4. YC (S-video)
5. Composite Video
2. Analog audio
1. Balanced and unbalanced signals
2. Types of microphones
3. Types of loudspeaker systems
3. Basic environmental factors
1. Appropriate displays for various scenarios
2. Aspect ratios
4. Cabling and connectors
1. Coaxial
2. Twisted pair
3. structured cable (shielded or unshielded twisted pair; ie, Cat5/5e/6)
5. Connectors
1. BNC
2. RCA
3. RJ45
4. XLR
5. HD15
6. DB9

There was more, but those were some high points that I remember. Some of this still fits; a loudspeaker is still a loudspeaker, and balanced audio is still usually connected to a 3-pin XLR the same way (1 is shield, 2 is hot, three is negative). S-Videoand component video, however, seem all but gone from professional installations. If I were building a knowledge base today (and I am, every day), I'd include:

1. Digital Video
1. TMDS (DVI and HDMI)
2. Mini-packet (Displayport) 
2. Data Networks
1. address layers
2. Firewalls and other security concerns
3. Digital audio
1. SPIDF
2. Cobranet
3. AVB
4. Fiber transmission
1. Singlemode
2. multimode

The more interesting question is how this list would look tomorrow. What are we learning now that will soon be obsolete, and what is lurking on the horizon which will become a core skill.