Convertible M codes

[cuda hunter]

I am noticing that I have record of 5 convertibles, 3 cudas and 2 challengers that do not have any M codes including the M21 that is on every other tag I have record of including several verts.   All B Hamtramck built cars
  Can someone explain why some 27 cars have M codes and others do not. 

[Skdmark]

M21 is drip rail moldings.
Convertibles don't have them due to the drop top.

[Mr Cuda]

 I've always thought m21 code was unnecessary as e bodies can't be built without drip rail mouldings.
Tail panel trim is standard with the cuda package,  and so is rocker and belt moulding.
Mine has m25 and m31 on the tag.

[cuda hunter]

Most have M31 body belt moldings on the fender tags.

Were body belt moldings not required on convertibles? 

[Mr Cuda]

Most have M31 body belt moldings on the fender tags.

Were body belt moldings not required on convertibles?

No, but they came standard with all BS package cars. I don't know dodge.
And obviously they didn't come on BH cars

[cuda hunter]

Why "obviously" not on BH cars? 

Just because BH's did not get extra trim on anything? 

I have not had a convertible, much less any convertible parts and have had very little to no exposure to any convertibles aside from pictures on the web. 

[Mr Cuda]

 On your opening post, I  hope you weren't lumping barracuda in with your cuda count.
Not many m codes on barra, but gran coupe will have codes, but with different mouldings

[cuda hunter]

Yes, I was lumping.  That's why I am asking. 
Not sure on the differences.  Especially with challengers as I have very little experience with challengers. 

So then, BH cars would be without M codes unless they were a special order item.  Is that safe to say? 

[Mr Cuda]

 From reading on here, Dan pointed out that some early production bs converts made it out without belt mouldings,  but in theory,  they all had it.
And, no I don't believe it was available as special order on a bh.
Here's a tag from today's lost hemi post for sale.

[6bblgt]

STANDARD MOULDINGS (indicated on a fender tag) on a 1970 convertible:
BH27 = NONE
BP27 = M25, M31
BS27 = M25, M31, M88 ** (some mid-September to mid-October 1969 SCHEDULED 'cudas are missing M31)

JH27 = NONE
JS27 = NONE

most (non-STANDARD) mouldings are available as stand alone OPTIONS or as part of a package