From 80e118b00145c348720e214e05a028949d0fc762 Mon Sep 17 00:00:00 2001
From: ferdymercury <ferdymercury@users.noreply.github.com>
Date: Mon, 11 Mar 2024 10:00:55 +0100
Subject: [PATCH 1/2] [skip-ci] [io] Collapse data format details of TFile
 class.

Supersedes https://github.com/root-project/root/pull/9616
---
 io/io/src/TFile.cxx | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/io/io/src/TFile.cxx b/io/io/src/TFile.cxx
index 560a069d1fdc7..e5aad2dffb296 100644
--- a/io/io/src/TFile.cxx
+++ b/io/io/src/TFile.cxx
@@ -13,6 +13,11 @@
 \file TFile.cxx
 \class TFile
 \ingroup IO
+\brief A ROOT file is an on-disk file, usually with extension .root, that stores objects in a file-system-like logical structure, possibly including subdirectory hierarchies.
+\sa \ref IO
+
+<details>
+<summary>ROOT file data format specification</summary>
 
 A ROOT file is composed of a header, followed by consecutive data records
 (`TKey` instances) with a well defined format.
@@ -21,6 +26,7 @@ The first data record starts at byte fBEGIN (currently set to kBEGIN).
 Bytes 1->kBEGIN contain the file description, when fVersion >= 1000000
 it is a large file (> 2 GB) and the offsets will be 8 bytes long and
 fUnits will be set to 8:
+
 Byte Range      | Record Name | Description
 ----------------|-------------|------------
 1->4            | "root"      | Root file identifier
@@ -69,7 +75,10 @@ Byte Range      | Member Name | Description
 Begin_Macro
 ../../../tutorials/io/file.C
 End_Macro
+
 The structure of a directory is shown in TDirectoryFile::TDirectoryFile
+
+</details>
 */
 
 #include <ROOT/RConfig.hxx>

From a7045f5d5eb4488241ef1fb47c0f1cd17eb7aad9 Mon Sep 17 00:00:00 2001
From: ferdymercury <ferdymercury@users.noreply.github.com>
Date: Mon, 11 Mar 2024 10:08:16 +0100
Subject: [PATCH 2/2] [skip-ci] cross-reference markdown docu with link as well
 as human-readable

as requested by pcanal
---
 io/io/src/TFile.cxx | 1 +
 1 file changed, 1 insertion(+)

diff --git a/io/io/src/TFile.cxx b/io/io/src/TFile.cxx
index e5aad2dffb296..4acb335a7511e 100644
--- a/io/io/src/TFile.cxx
+++ b/io/io/src/TFile.cxx
@@ -15,6 +15,7 @@
 \ingroup IO
 \brief A ROOT file is an on-disk file, usually with extension .root, that stores objects in a file-system-like logical structure, possibly including subdirectory hierarchies.
 \sa \ref IO
+\sa \ref rootio (or `io/doc/TFile` folder in your codebase)
 
 <details>
 <summary>ROOT file data format specification</summary>