diff --git a/README.md b/README.md
index d0559aab218e95f4c790da5708ad276d899a4279..9a39aaa86837002cdc79d83a0270045ef1dcb25b 100644
--- a/README.md
+++ b/README.md
@@ -89,6 +89,23 @@ The idea is to write as much generic code  as possible, so this can be used by a
 | `BEAMLINE`         | Optional, name of beamline/interaction region to build first | `ip6` or `ip8`                                      | Not used if undefined                |
 | `BEAMLINE_VERSION` | Branch or tagged version to use                              | Same as                                             | Default typically `main` or `master` |
 
+#### Other Configurable Variables 
+
+
+| Variable           | Meaning and use                                              | Examples                                            | Notes                                                                                         |
+| :---               | :---                                                         | :---                                                | :---                                                                                          |
+| `DETECTOR_CONFIG`  | Name of a top level detector description (xml) file          | `epic_far_forward_only`                             | These should not be required for well developed benchmarks. Can be useful developing new bms. |
+| todo :             | default value for `DETECTOR_CONFIG`?                         |                                                     |                                                                                               |
+#### Predefined Variables
+
+Do not override these values. 
+
+| Variable          | Meaning and use                                  | Value                           | Notes                                                    |
+| :---              | :---                                             | :---                            | :---                                                     |
+| `LOCAL_PREFIX`    | Installation path for `common_bench`             | `.local`                        | First searched via `$PATH`,`$LD_LIBRARY_PATH`, etc.      |
+| `DETECTOR_PREFIX` | Path for downloading repos and build directories | `$LOCAL_PREFIX/detector`        |                                                          |
+| `DETECTOR_PATH`   | Path to top level detector description files     | `$LOACL_PREFIX/share/$DETECTOR` | This is where various `DETECTOR_CONFIG`s should live too |
+
 #### Build Strategy
 
 First, let's start with the underlying assumptions: 
@@ -96,15 +113,14 @@ First, let's start with the underlying assumptions:
  - Development necessitates rebuilding some of the packaged software. Here we need to avoid unintentionally using the container packaged version we want to supplant.
  - This problem persists across CI jobs, triggered pipelines, and working locally.
 
-In the case  
-
+todo
 
 #### Data Flow: Artifacts Vs dedicated storage
 
-
+todo
 
 
 ### For benchmarks
 
-
+todo