2.5 explanation

2-IOC-deployment.md

@@ -164,6 +164,18 @@ $
 ```
 </details>
 
+<details>
+<summary>what does this mean?</summary>
+
+We are using a synApps release of EPICS, which is a set of pre-built support modules for EPICS. The ``SUPPORT`` variable is defined to point to the directory where the synApps support modules are installed: 
+**/APSshare/epics/synApps_6_2_1/support**.
+
+The ``-include`` directive is used to include the **configure/RELEASE** file from the synApps support module directory, which sets various EPICS-related environment variables, including ``EPICS_BASE``, as needed for building the IOC.
+
+Therefore, we do not need to explicitly set the ``EPICS_BASE`` variable in your **configure/RELEASE** file because it is already set in the synApps support module's **configure/RELEASE** file.
+
+</details>
+
 ### 2.6 Build the IOC (attempt #2)
 
 If following the build succeeds, skip to step 2.9