diff --git a/docsite/rst/playbooks_lookups.rst b/docsite/rst/playbooks_lookups.rst
index 2fce518bf7..007f225593 100644
--- a/docsite/rst/playbooks_lookups.rst
+++ b/docsite/rst/playbooks_lookups.rst
@@ -67,7 +67,9 @@ This length can be changed by passing an extra parameter::
 
         (...)
 
-.. note:: If the file already exists, no data will be written to it. If the file has contents, those contents will be read in as the password. Empty files cause the password to return as an empty string        
+.. note:: If the file already exists, no data will be written to it. If the file has contents, those contents will be read in as the password. Empty files cause the password to return as an empty string.
+
+Caution: Since this runs on the ansible host as the user running the playbook, and "become" does not apply, the target file must be readable by the playbook user, or, if it does not exist, the playbook user must have sufficient privileges to create it. (So, for example, attempts to write into areas such as /etc will fail unless the entire playbook is being run as root).
 
 Starting in version 1.4, password accepts a "chars" parameter to allow defining a custom character set in the generated passwords. It accepts comma separated list of names that are either string module attributes (ascii_letters,digits, etc) or are used literally::