# 15.5. 1.6.x Branch

- Upgrade Notes
- Version 1.6.0

## 15.5.1. Upgrade Notes

The Proxy Authentication handler was renamed to `proxy_authentication_handler` to follow the `*_authentication_handler` form of all other handlers. The old `proxy_authentification_handler` name is marked as deprecated and will be removed in future releases. It’s strongly recommended to update `httpd/authentication_handlers` option with new value in case if you had used such handler.

## 15.5.2. Version 1.6.0

- COUCHDB-2200: support Erlang/OTP 17.0 #35e16032
- Fauxton: many improvements in our experimental new user interface, including switching the code editor from CodeMirror to Ace as well as better support for various browsers.
- Add the `max_count` option (UUIDs Configuration) to allow rate-limiting the amount of UUIDs that can be requested from the /_uuids handler in a single request (CVE 2014-2668).
- COUCHDB-1986: increase socket buffer size to improve replication speed for large documents and attachments, and fix tests on BSD-like systems. #9a0e561b
- COUCHDB-1953: improve performance of multipart/related requests. #ce3e89dc
- COUCHDB-2221: verify that authentication-related configuration settings are well-formed. #dbe769c6
- COUCHDB-1922: fix CORS exposed headers. #4f619833
- Rename `proxy_authentification_handler` to `proxy_authentication_handler`. #c66ac4a8
- COUCHDB-1795: ensure the startup script clears the pid file on termination. #818ef4f9
- COUCHDB-1962: replication can now be performed without having write access to the source database (#1d5fe2aa), the replication checkpoint interval is now configurable (#0693f98e).
- COUCHDB-2025: add support for SOCKS5 proxies for replication. #fcd76c9
- COUCHDB-1930: redirect to the correct page after submitting a new document with a different ID than the one suggested by Futon. #4906b591
- COUCHDB-1923: add support for attachments and att_encoding_info options (formerly only available on the documents API) to the view API. #ca41964b
- COUCHDB-1647: for failed replications originating from a document in the _replicator database, store the failure reason in the document. #08cac68b
- A number of improvements for the documentation.