This file is indexed.

/usr/share/doc-base/zsh is in zsh-doc 5.0.2-3ubuntu6.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
Document: zsh
Title: Z Shell Manual
Author: Z-Shell workers
Abstract: This guide documents Zsh, a freely available UNIX command
 interpreter (shell), which of the standard shells most closely
 resembles the Korn shell (ksh), although it is not completely
 compatible.
Section: Shells

Format: info
Index: /usr/share/info/zsh.info.gz
Files: /usr/share/info/zsh.info*

Format: HTML
Index: /usr/share/doc/zsh-doc/html/zsh_toc.html
Files: /usr/share/doc/zsh-doc/html/*.html

Format: PDF
Files: /usr/share/doc/zsh-doc/zsh.pdf