diff --git a/sphinx/texinputs/sphinx.sty b/sphinx/texinputs/sphinx.sty
index 31f0fb97b28..a8647dbe7bb 100644
--- a/sphinx/texinputs/sphinx.sty
+++ b/sphinx/texinputs/sphinx.sty
@@ -311,8 +311,6 @@ will be set to white}%
 % Except that \sphinxbox is for boxing inline elements (no linebreak, no
 % pagebreak).
 %
-% (this addition happens in a descendant commit of this one)
-%
 % MEMO: the 6.2.0 refactoring induced a change that the default \fboxrule used
 % by verbatimborder and shadowrule is now not expanded to its value immediately in
 % preamble (no assignment to a \dimen register is done, only storage in a
@@ -361,6 +359,8 @@ will be set to white}%
 \spx@tempa{spx@attention@}{div.attention_}{attentionborder}{1pt}
 \spx@tempa{spx@danger@}   {div.danger_}   {dangerborder}   {1pt}
 \spx@tempa{spx@error@}    {div.error_}    {errorborder}    {1pt}
+% this one new at 6.2.0:
+\spx@tempa{spx@box@}      {box_}          {boxborder}      \fboxrule
 % Set default box-decoration-break style for codeblocks to slice
 \spx@pre@border@opentrue % new default at 6.0.0: slice, not clone
 
@@ -401,12 +401,11 @@ will be set to white}%
 \spx@tempa{spx@attention@}{div.attention_}  {\dimexpr.6\baselineskip-\spx@attention@border\relax}
 \spx@tempa{spx@danger@}   {div.danger_}     {\dimexpr.6\baselineskip-\spx@danger@border\relax}
 \spx@tempa{spx@error@}    {div.error_}      {\dimexpr.6\baselineskip-\spx@error@border\relax}
+\spx@tempa{spx@box@}      {box_}            \fboxsep % new at 6.2.0
 % define legacy verbatimsep key as alias of pre_padding key
 \expandafter\let\expandafter\KV@sphinx@verbatimsep\csname KV@sphinx@pre_padding\endcsname
 % define legacy shadowsep key as alias of div.topic_padding key
 \expandafter\let\expandafter\KV@sphinx@shadowsep\csname KV@sphinx@div.topic_padding\endcsname
-% (temporary explanation: this next comment and code line belong to a descendant
-%  commit down the line for \sphinxbox support, left-overs from a rebase)
 % also define a boxsep key as alias of box_padding key, because we defined boxborder
 % boxborder was defined only as collateral of batch definitions so some hesitation
 % we do keep these boxborder and boxsep as they configure the probably two most
@@ -438,6 +437,7 @@ will be set to white}%
 \spx@tempa{spx@attention@}{div.attention_}  \z@
 \spx@tempa{spx@danger@}   {div.danger_}     \z@
 \spx@tempa{spx@error@}    {div.error_}      \z@
+\spx@tempa{spx@box@}      {box_}            {3pt}% new and tentative at 6.2.0
 
 % Shadow keys
 %
@@ -455,6 +455,7 @@ will be set to white}%
 \spx@tempa{spx@attention@}
 \spx@tempa{spx@danger@}
 \spx@tempa{spx@error@}
+\spx@tempa{spx@box@}% new at 6.2.0
 %
 \def\spx@tempa#1{% #1 = macro prefix
   \expandafter\spx@tempb
@@ -495,6 +496,7 @@ will be set to white}%
 \spx@tempa{spx@attention@}{div.attention_}
 \spx@tempa{spx@danger@}   {div.danger_}
 \spx@tempa{spx@error@}    {div.error_}
+\spx@tempa{spx@box@}      {box_}% new at 6.2.0
 
 % Support for legacy shadowsize
 % This definition was broken at 5.1.0 and fixed at 6.1.2
@@ -567,6 +569,7 @@ will be set to white}%
 \spx@tempa{spx@attention@}{div.attention_}  {sphinxattention}
 \spx@tempa{spx@danger@}   {div.danger_}     {sphinxdanger}
 \spx@tempa{spx@error@}    {div.error_}      {sphinxerror}
+\spx@tempa{spx@box@}      {box_}            {sphinxbox}% new at 6.2.0
     % Keep legacy sphinxsetup interface for warning type notices
     \def\spx@tempa#1#2{% #1 = option prefix, #2 = legacy option prefix
       \expandafter\let\csname KV@sphinx@#2BorderColor\expandafter\endcsname
@@ -680,6 +683,13 @@ will be set to white}%
 
 %% FRAMED ENVIRONMENTS
 %
+% \sphinxbox added at 6.2.0, support code in sphinxpackageboxes
+% some of these defaults are already set, we repeat here via \sphinxsetup
+\sphinxsetup{boxborder=\fboxrule,
+             boxsep=\fboxsep,
+             box_border-radius=3pt,
+% border left without specific color, i.e. uses a priori black
+             box_background-TeXcolor=VerbatimColor}%
 \RequirePackage{sphinxpackageboxes}
 \def\spx@RequirePackage@PictIIe{%
 \IfFileExists{pict2e.sty}
diff --git a/sphinx/texinputs/sphinxpackageboxes.sty b/sphinx/texinputs/sphinxpackageboxes.sty
index c894f4eed0c..c30ea1d6e0a 100644
--- a/sphinx/texinputs/sphinxpackageboxes.sty
+++ b/sphinx/texinputs/sphinxpackageboxes.sty
@@ -135,6 +135,24 @@
   \fi
 }
 
+%%%%%%%%%%%%%%%%
+% \sphinxbox (added at 6.2.0)
+%
+% For an inline box, possibly rounded.
+\newcommand\sphinxbox[1][]{% #1 stands for the options, they are... optional!
+  \begingroup
+    \sphinxsetup{#1}% supposedly only "box" related options used here,
+    % setting other options is possible but will have a priori no effect
+    \spx@boxes@fcolorbox@setup
+        {box}
+        {sphinxboxBorderColor}
+        {sphinxboxBgColor}
+        {sphinxboxShadowColor}%
+    \setbox0\hbox\bgroup\aftergroup\spx@boxes@sphinxbox@a
+    \let\next=%
+}
+\def\spx@boxes@sphinxbox@a{\spx@boxes@fcolorbox{\box\z@}\endgroup}
+
 %%%%%%%%%%%%%%%%
 % MACROS
 %