[yocto] [license][PATCH 2/2] ref-manual: Add description for SPDX license operators

[Sergei Miroshnichenko]

Add examples of "OR", "AND" and "WITH" operators usage.

Reference:
https://spdx.org/sites/spdx/files/SPDX-2.0.pdf Appendix IV: SPDX License Expression

Signed-off-by: Sergei Miroshnichenko <sergeimir at emcraft.com>
---
 documentation/ref-manual/ref-variables.xml | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index d55bccd..5892530 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -7106,12 +7106,17 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
                     <itemizedlist>
                         <listitem><para>Do not use spaces within individual
                             license names.</para></listitem>
-                        <listitem><para>Separate license names using
-                            | (pipe) when there is a choice between licenses.
+                        <listitem><para>Separate license names using the
+                            | (pipe) or "OR" operators when there is a choice
+                            between licenses.
                             </para></listitem>
-                        <listitem><para>Separate license names using
-                            & (ampersand) when multiple licenses exist
-                            that cover different parts of the source.
+                        <listitem><para>Separate license names using the
+                            & (ampersand) or "AND" operators when multiple
+                            licenses exist that cover different parts of the source.
+                            </para></listitem>
+                        <listitem><para>Separate license and exception names using the
+                            "WITH" operator when a set of license terms apply except
+                            under special circumstances.
                             </para></listitem>
                         <listitem><para>You can use spaces between license
                             names.</para></listitem>
@@ -7132,6 +7137,12 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
      LICENSE = "LGPLv2.1 | GPLv3"
      LICENSE = "MPL-1 & LGPLv2.1"
      LICENSE = "GPLv2+"
+     LICENSE = "LGPL-2.1 OR MIT"
+     LICENSE = "LGPL-2.1 OR MIT OR BSD-3-Clause"
+     LICENSE = "LGPL-2.1 AND MIT"
+     LICENSE = "LGPL-2.1 AND MIT AND BSD-2-Clause"
+     LICENSE = "GPL-2.0+ WITH Bison-exception-2.2"
+     LICENSE = "MIT AND (LGPL-2.1+ AND BSD-3-Clause)"
                     </literallayout>
                     The first example is from the recipes for Qt, which the user
                     may choose to distribute under either the LGPL version
-- 
2.1.0