I have created a python filter which replaces user-definable abbreviations (stored in a dictionary file and/or in a pandoc markdown source document's metadata) with their expansions. This is my attempt to replicate the kind of possibilities offered by LaTeX macros like \newcommand{\osh}{oshigami}, i.e. write '\osh', get 'oshigami' when the document is processed. In the past I've found this very useful for maintaining consistency throughout a document, and I missed this when I moved to writing in markdown.

I'm not really a programmer but - based on what I could understand from looking at other python filters out there - I managed to slap together something which seems to do what I want it to. However, I'm not really competent to judge whether it's fit for 'general consumption' and I am hoping there might be people out there willing to spend a few minutes to take a look at it and advise me on what needs to be done to make it 'roadworthy'. 

This is the repository: https://github.com/scokobro/pandoc-abbreviations

Thanks in advance!