Regarding writing custom filter for GNU Aspell

Respected members,

     Recently I was trying to use GNU Aspell to find spelling mistakes 
in our documentation. Our documentation is in .rst 
(https://en.wikipedia.org/wiki/ReStructuredText) file format. I observed 
the available list of filters but unable to find any for 
ReStructuredText format. I skimmed latest documentation available here 
http://aspell.net/man-html/index.html but unable to get any reference of 
writing custom filters for GNU Aspell. I tried to place a search on the 
archives of this mailing list but didn't got any discussion on this 
topic. Below are my questions.

1. Is it possible to write custom filters for GNU Aspell?

2. If the answer to above question is yes then please share the 
reference. I want to write filter for checking ReStructuredText format 
document and will share back to this community as free software. I 
request to share if any filter is existing for ReStructuredText.

Many thanks!