As I was going through the whole thing I realized that all of this was originally designed such that shields were a type of armor but then when more feats and other optional features were created later on that were meant to interact only with armor that wasn't supposed to include shields this categorization became problematic.  So, there was official errata that altered the text in the Getting Into and Out of Armor section in order to split those into separate subcategories, but then they didn't update the text in the rest of the section.  So, we are left with text which uses the overall category of Armor and Shields for some rules and then in other places it is specified that Armor is a distinct subcategory from Shields and so the section as a whole is less consistent than it was before.  As a result, instead of it being 100% obvious that the proficiency rules apply to both Armor and Shields, it is now only 99% obvious.

That's my point, its interpretation not rules as written.  You interpret it a they are the same, I read as that they are not.  Because you are not 100% sure means the rules aren't clear.  I couldn't care less about what the intended meaning was, only what is actually written.  Its the same reason I couldn't do religious studies at school.  You are either clear, concise and consistent or you opinion is by virtue on inconsistency irrelevant.

I think we can completely agree that there are many things we 100% are the same on, no ambiguity, which are written in such a way as to be free of contradiction or confusion.  This is not the case with this, either in terms of wording or logic.  There are many simple fixes that would sort this out but there is no way that you shouldn't get the AC boost from wielding a shield irrespective of whether it is a buckler or a scutum.  

Well, in current 5e you get the AC boost from the shield no matter what -- I'm not sure what your argument is there?

I just now saw some of your previous comments that ended up being buried within the quote in your last post.  Your weapon example with the Monk makes no sense.  Monks by default are proficient in simple weapons and shortswords.  What in the world does that have to do with armor and shields?

The point about the Armor table is that you have to look at the version in the PHB.  It's possible that the table itself was changed via errata also and I am just not aware of it.  But assuming otherwise, the table in the PHB clearly shows what I was saying in that post.  That version of the table has an overall title within the table itself labelled "Armor".  Then, under this, the left-most column of the table data is labelled with a heading called "Armor".  This data lists the item subcategories and the item names.  "Shield" is one of the 4 subcategories listed in that column.  It contains one item called "shield".  Everything in this table belongs to the same category of items.  In this table, that category is referred to as "Armor".  However, the heading for the section of text in which this table is located refers to this category as "Armor and Shields".  Within the text for that section the category is sometimes referred to as "Armor".  It's definitely not great word usage and it has become more confusing after the errata to the Getting Into and Out of Armor section which now creates another (third) level of categorization.

Graphically, we have:

(1)  Armor and Shields (often referred to as "Armor" for brevity)

               |                                                                       |

(2)     Shields                                                           Armor

               |                                                       |               |               |

(3)     Shields                                           Heavy    Medium    Light

Before the errata, there was no (2).  So, it was more clear that the rules for proficiency referred to (1).  They still refer to (1) today, but it's less obvious.  I agree that it should be cleaned up in a future release.

Some have said the the user doesn't get the AC because if you don't have proficiency you don't know how to wear it effectively.  I disagree with that statement.

The monk statement waa more demonstrate that a table (weapons table) can have items listed that are separate also, just like it separates simple and martial just because a ruling applies to simple it doesn't automatically apply to martial.

Personally I think the 2 biggest points in favour of my position are;

A) "The armour table collects the most commonly available types of armour found in the game and separates them in to three categories; light armour, medium armour and heavy armour.  Many warriors supplement their armour with a shield.

B) On the armour table "Shield" is its own category, but more importantly it states explicitly the it is not subject to a stealth penalty or strength requirement.

I think that the AC comments had to do with some changes that are being made in the new UA version.  In 5e, the only time that you wouldn't get the AC is if the shield is not properly donned and instead is merely held.  Once donned, you get the AC regardless of proficiency.

I'm not sure how the lack of stealth penalty or strength requirement for a shield says anything -- there are plenty of other items in the Armor table which also lack these penalties.

I can definitely see how the proficiency rules can be read the way that you are thinking.  In that case, I suppose the changes to the Getting Into and Out of Armor section via errata may have accidentally "broken" the proficiency rules.  I still don't read it that way, but it is one reasonable interpretation.

That's really all it comes down to.  How you read it?  The strength and stealth is more to do with those being related to stats that are disadvantaged.  But yes, I do feel they are broken, or at least open to fair and respectful discussion.  I don't care if I'm wrong about something, its happened many times and will happen many more, I just want to know why.

So I started this whole down the rabbit hole bit of research because I am currently stuck in bed with rona, and am working on a character I play (melee Wizard) and  while I don't NEED a shield it would make it easier to balance my stats as I would need high INT and DEX but I don't want to be completely inept at the other stats.  So after running my findings past the DM and requesting they read the information and make a ruling I played them last night.

The Wizard can definitely don a Shield and get the +2 AC, you just wouldn't be able to cast any spells.

I agree completely with you about the no casting if you  for instance wear a shield, it 100% unequivocally states that. 

I applaud you using the phrase "don a shield", the sentiment is not lost on me, and a subtle yet polite quip with words is worthy of more respect and acknowledgement than an insult would ever be (not that I'm saying you would be insulting).  Which is why as part of the build I took War Caster.  I wanted to build an unusual wizard who fights up close and personal (suits the backstory I created) so I was deep reading every idea I had to try to make it work RAW, then I ran it past the DM as their ruling is really the only one that matters.

In all honesty, this has been an interesting and enjoyable debate on the topic, and while I know both have differing points of view of the result we could both acknowledge each others arguments reasonably and without too much sarcasm in the responses at times.  *Tips hat*

Have a Merry Christmas.

One thing I'd like to point out about the shields are/are not armor: the DDB character builder explicitly labels them Armor, not Equipment.