With each request to bfluhr.com a log line is written to a log file. This logline records your IP address, the HTTP request method and the protocol’s version in use. It further documents the requested URL, the status code of the response, the number of bytes transferred with the response, the referer and your user agent. According to Dreamhost the resulting log files are stored for 3 days.
In order to make it easier to distinguish links to external websites from internal links, any external links are suffixed with this ⍆-symbol, if your browser supports CSS.
MathJax
Some of my notes are available in different formats, one of them HTML. For the HTML version I use the copy of MathJax distributed by JSDelivr. If you access these HTML notes your browser will make additional HTTP requests to JSDelivr. As a result JSDelivr's privacy policy applies. Furthermore, MathJax makes use of cookies. If this is a concern, then I recommend downloading the PDF version instead. (The PDF and HTML versions contain the same content.)
Multidoc
If you use multidoc-rules with it’s default options for typesetting mathematical documents, then any time you build a document from scratch you download normalize.css from GitHub. Therefore GitHub’s privacy policy applies. Further multidoc’s HTML output references MathJax as well and thus the above applies to HTML files created with multidoc as well.