Btw, the new 8260.19L is seemingly all botched up. The Table of Contents doesn't match up with the section numbers after 2-10-3. It looks like the revised 2-10-3 is missing. It was supposed to be about "unplanned holding" and the switch in terminology from all "designated reporting points" to only fixes that were "compulsory reporting points". Made me wonder if holding pattern evaluation at MEA was always only meant to done at the latter, but was loosely described as the former, which would have been a huge difference in workload for the TERPsters.
Okay, this is going to get a little murky. Everything below can be considered MY OPINION only, except where I reference the regulations...
I agree that the table of contents has errors (it's the 8260.19i, but capital "i", not lower case "L"). It is my opinion (my opinion only), that the removal of 2-10-3 was intentional, in that the intent was to remove the language about unplanned holding, and therefore remove the concept of unplanned holding.
There is no criteria for how to evaluate unplanned holding in 8260.3E (nor was there in the predecessor reg for holding, the 7130.3). Logically, if at a VOR, if holding could be in any direction, then an evaluation would essentially consist of evaluating 360 holding patterns. Or, I suppose 720 holding patterns if left turns are considered too. What this looks like in practice is a giant circle drawn around the VOR, kind of like an MSA but not as big. However, this methodology is not spelled out in the holding TERPS.
In practice, however, the exception in the previous .19H about documenting any "necessary limitations" on Form 8260-2 is applied routinely, by adding the statement "Holding limited to established patterns" on the -2. This statement disallows unplanned holding. If you go to the link posted above for 8260-2 forms, you will be hard pressed to find one that HAS holding but does NOT have this statement. Here's an example, it has the statement:
https://nfdc.faa.gov/webContent/content8260/OK_ROLLS_REV17.pdf
In the .19I, the explanatory paragraph was removed but the example wording remained.
Now, in a quirk of practice vs regulations, this statement is only added to fixes that have established holding documented. If a fix does not have established holding of any sort, it does not get the statement. Does this mean that unplanned holding IS allowed at this fix? Heck if I know. I'd be curious to see what any ATCer's take is on this, if they even access these forms for any purpose.
Moreover, a NAVAID (typically VOR in this use) that does not have established holding will not even HAVE a Form 8260-2 created for it. So there is no form on which to put the limitation.