pandoc/test/command/11013.md

% pandoc --csl command/chicago-fullnote-bibliography.csl -C --wrap=none -t plain
---
references:
- id: test10
  type: blog-post
  title: "Test 10: Lowercase username in brackets, Works!"
  author:
  - literal: "[deleted]"
  container-title: "Reddit"
  issued:
    year: 2009
...

blah [@test10].
^D
blah.[1]

[deleted]. “Test 10: Lowercase Username in Brackets, Works!” Reddit, 2009.

[1] [deleted], “Test 10: Lowercase Username in Brackets, Works!” Reddit, 2009.