LocationMatch Regular Expression Behavior

I am trying to set a bunch of url based rules in Apache using LocationMatch and the regex seems to behave in a way I don't understand.
I've tried looking for the documentation, but I'm not very clear on what WRT is for my problem ... and other questions / answers around interwebs.

Here is my Location directive and a general example of the structure of my LocationMatch directives:

<Location />
    Header set X-Intelligence "CatchAll"
</Location>

<LocationMatch "\.(pdf)$">
    Header set X-Intelligence "pdf1"
</LocationMatch>

      

        
        
        
      

    

• These directives are located inside the virtual host using ssl.
• I am not using any other Location or LocationMatch directives in other configurations.
• The LocationMatch directives all appear after my Location CatchAll directive.
• Everything works fine when I only use the directive <Location />
  
  .

I noticed some differences between the regex used here and the regex that I have experience with.

• Using start and end codes does not work.
• Using end modifier tags like / i / g doesn't work.
• Other behavioral differences below

I've tried many different things, but here are some examples of my results:

1.

<LocationMatch "(?i)\.(pdf)$">
    Header set X-Intelligence "pdf1"
</LocationMatch>

      

        
        
        
      

    

• The above seems to match all .pdf and .PDF urls.

However:

<LocationMatch "\.(pdf)$">
    Header set X-Intelligence "pdf1"
</LocationMatch>

      

        
        
        
      

    

• Doesn't match urls of .pdf extension.
• .pdfs don't end up in CatchAll (404 not found displayed).
• .PDF (capitals) do end up in CatchAll.

...
2. Not like this:

<LocationMatch "\.(docx?)$">
    Header set X-Intelligence "doc2"
</LocationMatch>

      

        
        
        
      

    

• The above matches my .docx urls.

However:

<LocationMatch "\.(doc)$">
    Header set X-Intelligence "doc2"
</LocationMatch>

<LocationMatch "\.(docx)$">
    Header set X-Intelligence "doc22"
</LocationMatch>

      

        
        
        
      

    

• The above do not match .docx urls.
• Doesn't hit CatchAll (404 not found).
• I tried reordering the order and it still gives the same results.

Not sure what is going on, but the behavior is completely not what I expect. Anyone have any ideas on what I might be doing wrong or what I am not understanding?

Open all suggestions to make this question better. Thank.