diff --git a/.dir-locals.el b/.dir-locals.el
new file mode 100644
index 0000000..285f530
--- /dev/null
+++ b/.dir-locals.el
@@ -0,0 +1,5 @@
+;; -*- no-byte-compile: t; -*-
+
+((nil
+  (bug-reference-url-format
+   . "https://github.com/leanprover-community/lean4-mode/issues/%s")))
diff --git a/README.org b/README.org
index 4c16413..7ec4276 100644
--- a/README.org
+++ b/README.org
@@ -181,3 +181,13 @@ use it.  If you want to customize this behavior, e.g. if you'd like to
 use Emacs' built-in Flymake package instead of Flycheck while keeping
 later installed, then customize the ~lsp-diagnostics-provider~ user
 option accordingly.
+
+* Contributing
+
+When you contribute an addition or modification of a substantial part
+of Lean4-Mode, then you can add a personal copyright like =;;
+Copyright (c) 2024 John Doe= to the beginning of the respective files.
+
+You can use Emacs' built-in ~bug-reference-mode~ and
+~bug-reference-prog-mode~ to make in this repository to make mentions
+of issues like =#123= clickable.
diff --git a/lean4-mode.info b/lean4-mode.info
index 9847bf2..62e7f5b 100644
--- a/lean4-mode.info
+++ b/lean4-mode.info
@@ -32,6 +32,7 @@ _Lean-Mode_).
 * Installation::
 * Usage::
 * Configuration::
+* Contributing::
 
 -- The Detailed Node Listing --
 
@@ -258,7 +259,7 @@ Key         Description            Command
 ‘C-c ! p’   Go to previous error   ‘flycheck-previous-error’
 
 
-File: lean4-mode.info,  Node: Configuration,  Prev: Usage,  Up: Top
+File: lean4-mode.info,  Node: Configuration,  Next: Contributing,  Prev: Usage,  Up: Top
 
 3 Configuration
 ***************
@@ -291,23 +292,38 @@ Emacs' built-in Flymake package instead of Flycheck while keeping later
 installed, then customize the ‘lsp-diagnostics-provider’ user option
 accordingly.
 
+
+File: lean4-mode.info,  Node: Contributing,  Prev: Configuration,  Up: Top
+
+4 Contributing
+**************
+
+When you contribute an addition or modification of a substantial part of
+Lean4-Mode, then you can add a personal copyright like ‘;; Copyright (c)
+2024 John Doe’ to the beginning of the respective files.
+
+   You can use Emacs' built-in ‘bug-reference-mode’ and
+‘bug-reference-prog-mode’ to make in this repository to make mentions of
+issues like ‘#123’ clickable.
+
 
 
 Tag Table:
 Node: Top223
-Node: Installation1414
-Node: Brief and Generic Instructions1657
-Node: Detailed and Concrete Instructions2612
-Node: Instructions for Source-Based Use-Package3974
-Node: Native vc (Emacs 30 or later)4695
-Node: Doom-Emacs5484
-Node: Straight5910
-Node: Usage6410
-Node: lsp-mode7856
-Node: Flycheck8141
-Node: Configuration8690
-Node: lsp-mode (1)8856
-Node: Flycheck (1)9125
+Node: Installation1431
+Node: Brief and Generic Instructions1674
+Node: Detailed and Concrete Instructions2629
+Node: Instructions for Source-Based Use-Package3991
+Node: Native vc (Emacs 30 or later)4712
+Node: Doom-Emacs5501
+Node: Straight5927
+Node: Usage6427
+Node: lsp-mode7873
+Node: Flycheck8158
+Node: Configuration8707
+Node: lsp-mode (1)8894
+Node: Flycheck (1)9163
+Node: Contributing9648
 
 End Tag Table
 
diff --git a/lean4-mode.texi b/lean4-mode.texi
index 42a1be5..703be1e 100644
--- a/lean4-mode.texi
+++ b/lean4-mode.texi
@@ -39,6 +39,7 @@ known as @emph{Lean-Mode}).
 * Installation::
 * Usage::
 * Configuration::
+* Contributing::
 
 @detailmenu
 --- The Detailed Node Listing ---
@@ -296,4 +297,15 @@ use Emacs' built-in Flymake package instead of Flycheck while keeping
 later installed, then customize the @code{lsp-diagnostics-provider} user
 option accordingly.
 
+@node Contributing
+@chapter Contributing
+
+When you contribute an addition or modification of a substantial part
+of Lean4-Mode, then you can add a personal copyright like @samp{;;
+Copyright (c) 2024 John Doe} to the beginning of the respective files.
+
+You can use Emacs' built-in @code{bug-reference-mode} and
+@code{bug-reference-prog-mode} to make in this repository to make mentions
+of issues like @samp{#123} clickable.
+
 @bye