Doc: document error codes and proj_context_errno_string()

1 files changed, 20 insertions, 0 deletions

diff --git a/docs/source/development/reference/functions.rst b/docs/source/development/reference/functions.rst
index b37eacdd..5b559d55 100644
--- a/docs/source/development/reference/functions.rst
+++ b/docs/source/development/reference/functions.rst
@@ -388,6 +388,8 @@ Error reporting
     context is read. A text representation of the error number can be retrieved
     with :c:func:`proj_errno_string`.
 
+    Consult :ref:`error_codes` for the list of error codes (PROJ >= 8.0)
+
     :param P: Transformation object
     :type P: :c:type:`PJ` *
 
@@ -400,6 +402,8 @@ Error reporting
     transformation. A text representation of the error number can be retrieved
     with :c:func:`proj_errno_string`.
 
+    Consult :ref:`error_codes` for the list of error codes (PROJ >= 8.0)
+
     :param ctx: threading context.
     :type ctx: :c:type:`PJ_CONTEXT` *
 
@@ -464,6 +468,22 @@ Error reporting
 
     Get a text representation of an error number.
 
+    .. deprecated:: This function is potentially thread-unsafe, replaced by :c:func:`proj_context_errno_string`.
+
+    :param err: Error number.
+    :type err: `int`
+
+    :returns: `const char*` String with description of error.
+
+.. c:function:: const char* proj_context_errno_string(PJ_CONTEXT* ctx, int err)
+
+    .. versionadded:: 8.0.0
+
+    Get a text representation of an error number.
+
+    :param ctx: threading context.
+    :type ctx: :c:type:`PJ_CONTEXT` *
+
     :param err: Error number.
     :type err: `int`