How to Read the AD&D Rules: A Surprising rule about Encounter Distance

Remember this old gimmick where, in a fit of hubris, I tried to clarify and paraphrase the AD&D rules into a more concise text? Remember how badly I failed? 

It was pretty laughable, yes, but it also helped me understand rules that I never knew that I didn't know. Unknown unknowns, if you will. Most egregiously, I completely misunderstood the whole surprise segments thing. You can read the whole dreaded affair if you like. Or not, my feelings won't be hurt. (sniff)

In classic D-Chux fashion, I'm dragging this old pony out of the glue factory to abuse it some more, because I started reading the DMG again and, a few pages on from the surprise rules, I encountered the rules on Encounter Distance. Read on if you dare, my fellow dice chuckers...[pardon the horror show antics, this post was supposed to go up before Halloween but I overslept]

Distance

As in, how far apart two parties are when they come into contact. You might think this would be obvious based on the terrain, lighting, where the DM planned for the monsters to pop up in the dungeon, etc, but the DMG leads off the discussion with this sentence:

"When encounters occur, the distance between concerned parties will be 5"-10" (d6+4) subject to the following modifying factors..."

The author then lists off the following six factors: 

1. Line of sight, 
2. Noise, 
3. Actual Area, 
4. Planned or unplanned appearance, 
5. Surprise, and 
6. Light. 

Which is to say, use your head and figure out where first contact is most reasonably going to occur.  And because even a novice dungeon-master will be able to determine where contact will occur without even thinking to consult with the rules, this entire section has never been read by anyone.

And since no one ever read this section, no one uncovered this tidbit:

"Surprise can only be a factor in close encounter situations. If either or both parties are surprised, the distance must be either 1" to 3" or it must be less as determined by the actual area modifier." DMG, some page.

Or, as a loquaciousness-deprived person might put it: 

Parties must be within 30' of each other in order for surprise to occur.

Seems like a pretty important piece of information, right? But, even though Gygax just finished writing 12 paragraphs of befuddling text about surprise, he decided to obfuscate even further this crucial piece of information by placing it in a separate, and entirely superfluous, section of the book.