Heinlein and that which must not be named

I am a bit of a Heinlein fanatic and have been for nearly 60 years, not as long as my spanking obsession but a goodly time. I started appropriately enough with his juveniles when I was a juvenile and have since read everything he wrote that I could get my hands on. Over the years it became increasingly clear that my two obsessions were intertwined, from the early days when there were a few, but significantly many, throw away spanking references to his later novels, several of which have passages which might appear in this library.
Recently, at the recommendation of a library member, (his name will come to me eventually) I read Heinlein's Children a series of essays on his juveniles. It is the third book of Heinlein criticism or biography that I have read. I was struck in Heinlein's children by the depth of analysis, going so far as to offer some (to me seemingly flimsy) evidence that Rod in Tunnel in the Sky was black. With all this, neither this book nor any of the others I have read make the slightest mention of Heinlein's obvious interest in spanking.
It is not a matter of avoiding sex, the first volume of a planned 3 volume biography of Heinlein mentions his belief in and practice of open marriage, his and his first wife's attendance at nudist camps, and speculates at least lightly on his possible lovers while married to his first wife. It seems rather that this avoidance of the kangaroo, if not the elephant, in the room is specific to spanking.
While, surprisingly to those who know me, I do not have a crack pot theory to explain this peculiarity, it seems to me to be possibly related to the awkwardness with which dictionaries have traditionally handled the definition of our favorite word. Those of us of the preinternet generation, who spent our youths looking up "spanking" in any dictionary we could find, know what I mean, vagueness and circumlocution are characteristic of the definitions "to strike with the open hand, esp. on the buttocks" being one that springs to mind. The fact that it is used as discipline for children, the OTK posture, not to mention the important question of bareness, and a long list of other features are dealt with by ignoring. I have long thought that this sloppy lexicography was the result of a certain tingle elicited in the lexicographers which they preferred not to risk making public. Perhaps the same is true of Heinlein critics.

Well, I don't know about Heinlein but two mentions of note: often news accounts seem particularly blurry about items which seem to imply spanking. Reporters always say "beatings" or "struck with a stick[ belt, paddle etc.]; second, early Sharon Green novels (she is now clearly a spanko writer) described the heroine as being struck with a switch "below the small of the back". (Say where? Oh, you mean on her ass!)
Often there is clearly a huge reluctance to state the obvious.
Re Heinlein--isn't there a reference to caning in schools in Starship Troopers?

I must rise to defend the honor of a lady, the "below the small of the back" reference is from John Norman's GOR series (repeated in several of them if I remember correctly.) Ms Green's heroines were soundly and honestely spanked on their backsides or buttocks or something similar.

There is a flogging in Starship Troopers and a reference to school spanking or paddling, I don't think any of Heinlein's characters were even caned or threatened therewith as is appropriate for an American writer.

I don't agree, although this may have also been the case with the supremely lame GOR novels. I distinctly recall being irritated by this in the very first of the novels Sharon Green wrote about the agent who must accompany the barbarian Tammad in the first of the Terrilian novels. Yes, to her credit she later got it right and called a spank a spank, but she used PC euphemisms in this first one.

IIRC there's a classroom discussion, led by the (male) teacher but with quite active student involvement, of the use of corporal punishment as discipline for children--but primarily within a family setting. The participating students do seem to accept that having been spanked by their parents as youngsters helped them develop into responsible individuals, and the teacher favorably (via analogy) compares CP to other forms of behavior modification.

There are plenty of brief figurative references to spanking within STARSHIP TROOPERS, including even referring to a low-casualty attack on an enemy species' residential area as a "mere spanking" or something like that.

The only punitive implement (as opposed to an open hand) I recall being used in any of Heinlein's writings (although I haven't read anywhere close to all of them) is an elderly witch's shoe (applied OTK to the seat of a dwarf's pants) in MAGIC, INCORPORATED...--C.K.

Surprised no one has mentioned Glory Road, a Heinlein novel which contains several spanking references.
The hero clashes with a hot-tempered Empress who attempts to pull a sword on him. He tells her if she does he'll take it away from her, pull down her tights, and spank her with it. He also tells her if she says one more word out of line, she'll get spanked until she can't sit for a week.
Later on they become lovers, and he gives her a few spanks when they are in bed together.
The spanking threats are much more exciting than the actual spanking.

I agree with rsk about threats vs actual spankings in Glory Road, in fact I think in general, writing of erotic activities was not RAH's strong suit.

As for implements, a short investigation in Kessily's invaluable bibliography of spanking references in Heinlein's works reveals more references to switches than you could, well, shake a stick at, and a smaller number of references to belts. There are also numerous references to paddling, but it is not clear whether some or all refer to actual paddles or are just used as a generic term for spanking.