Add preview flag to Vim plugin (#3246)

[etc/vim.git] / docs / usage_and_configuration / black_as_a_server.md

diff --git a/docs/usage_and_configuration/black_as_a_server.md b/docs/usage_and_configuration/black_as_a_server.md
index 7d07e94e6bbd97146ea25b14e425c87e130bc2b0..a2d4252109a8595590edc7a18f6fe1ba0cedc556 100644 (file)
--- a/docs/usage_and_configuration/black_as_a_server.md
+++ b/docs/usage_and_configuration/black_as_a_server.md
@@ -4,6 +4,11 @@
 protocol. The main benefit of using it is to avoid the cost of starting up a new _Black_
 process every time you want to blacken a file.
 
+```{warning}
+`blackd` should not be run as a publicly accessible server as there are no security
+precautions in place to prevent abuse. **It is intended for local use only**.
+```
+
 ## Usage
 
 `blackd` is not packaged alongside _Black_ by default because it has additional
@@ -49,8 +54,11 @@ The headers controlling how source code is formatted are:
   command line flag. If present and its value is not the empty string, no string
   normalization will be performed.
 - `X-Skip-Magic-Trailing-Comma`: corresponds to the `--skip-magic-trailing-comma`
-  command line flag. If present and its value is not the empty string, trailing commas
+  command line flag. If present and its value is not an empty string, trailing commas
   will not be used as a reason to split lines.
+- `X-Preview`: corresponds to the `--preview` command line flag. If present and its
+  value is not an empty string, experimental and potentially disruptive style changes
+  will be used.
 - `X-Fast-Or-Safe`: if set to `fast`, `blackd` will act as _Black_ does when passed the
   `--fast` command line flag.
 - `X-Python-Variant`: if set to `pyi`, `blackd` will act as _Black_ does when passed the