Sure MikeP, in fact, I would say that I prefer talking about things that aren't bugs! Hopefully that doesn't bother any entomologists
The Hybrid filter is the same as the moving average filter, but it doesn't return any measurements until the whole filter block fills up for the first time. This delay's the first measurement, but ensures you never get an unfiltered (or partially filtered) reading. The reason it's called hybrid is because the first reading acts like the repeat filter, but every reading after that behaves like the moving average filter described on 5-54 in the manual. This was added for the most recent firmware release and so was included in the 1.0.01f Release Notes, rather than the Reference Manual, it'll be added to the Manual when we put out a new update to it.
The measurements on C-25 are example measurements preformed by our cal lab for the manual. So the "Typical reference DMM reading" values of 1.000157 and 9.999450 are the actual measured values of the specific resistors
we used for the manual example. You should use your own resistor or calibration source with nominal values of 1 Ohm and 10 Ohms, the actual value should just be close to that, but I don't think it's spec'd how close. Page C-4 lists the how to find the upper and lower limits, you simply use the accuracy listed in the specification: Actual Value +- (% of actual value + % of range)
For the full calibration report, the best thing to do is be sure to ask for it when you order your unit. If you got your unit recently, try emailing RMA at tek.com with your model number and serial number (they might need your calibration certificate number too). They keep the full data for some amount of time so they may still have it. Otherwise, you will need to ask for the full calibration report the next time you send your unit in. I think the full data costs a little bit extra for the DMM6500/10, maybe $10?
The 1/2 digit refers to the first digit in the reading, which can be either a 0 or a 1. So the DMM can read 6 full scale digits, where each can be any number 0-9, and one 1/2 digit that's either a 0 or a 1. A 1 would be the full scale of the range (i.e. 1.000000V), but most meters let you measure a little above the maximum of the range, often 20% in Keithley equipment. As far as I know, calling that a half digit is industry standard. I believe the unofficial formula is fractional digit = (max value)/(number of possible values), I say unofficial because it isn't always true. Keithley usually uses 1/2 digit to mean a digit that doesn't have a full 0-9 scale, other manufactures do similar. Even in the DMM6500, some measurements can read more than 1 in the first digit. Current for example has a 3A range, but it's still considered 6 1/2 digits, using the formula I gave would mean that particular range is 6 3/4 digits. It would be confusing to list the precise fractional digits for each range and function, so the whole meter is classed as a 6 1/2 digit.
Hopefully that answers your questions?
EDIT: Fixed when the Hybrid filter was released and where it's documented.