OpenFAST · andrew-platt · Aug 18, 2026 · Aug 19, 2026 · Aug 19, 2026 · Aug 19, 2026
diff --git a/docs/OtherSupporting/OutListParameters.xlsx b/docs/OtherSupporting/OutListParameters.xlsx
diff --git a/docs/_static/custom.css b/docs/_static/custom.css
@@ -0,0 +1,40 @@
+/* Set the screen width maximum a bit wider than default.  Improves readability on wide screens, but still scales down in width on smaller screen */
+.wy-nav-content {
+    max-width: 1200px !important; /* the default was 800.  allowing full width is too much on super wide screens */
+}
+
+
+/* Target the last column of any table and force word-wrapping */
+table.docutils td:last-child, 
+table.citation td:last-child {
+    white-space: normal !important;
+    word-break: break-word;
+    min-width: 300px; /* Adjust this to match your ~100 character preference */
+}
+
+/* rather than the above, for a targetted table approach, use the below one by adding the following at the table
+.. csv-table:: My Table Name
+   :class: wrap-last
+   :headers: "Command", "Description", "Very Long Comment"
+   :widths: 20, 20, 60
+*/
+/* Target only tables explicitly marked with the 'wrap-last' class */
+table.wrap-last td:last-child {
+    white-space: normal !important;
+    word-break: break-word;
+    min-width: 300px;
+}
+
+
+
+/* Mermaid diagrams: fill the content column rather than rendering at
+   natural size (mermaid only scales down, never up). sphinxcontrib-mermaid
+   2.x emits <pre class="mermaid">, older versions <div class="mermaid">,
+   so match the class alone. */
+.mermaid svg {
+    width: 70% !important;
+    max-width: 70% !important;
+    height: auto !important;
+    display: block;
+    margin: 0 auto;
+}
diff --git a/docs/conf.py b/docs/conf.py
@@ -283,6 +283,29 @@ def setup(app):
         objname="CMake configuration value",
         indextemplate="pair: %s; CMake configuration"
     )
+
+
+def setup(app):
+    # Register your new custom width override file
+    app.add_css_file('custom.css')
+
+    try:
+        app.add_css_file('css/math_eq.css')
+    except:
+        pass
+    app.add_object_type(
+        "confval",
+        "confval",
+        objname="input file parameter",
+        indextemplate="pair: %s; input file parameter"
+    )
+    app.add_object_type(
+        "cmakeval",
+        "cmakeval",
+        objname="CMake configuration value",
+        indextemplate="pair: %s; CMake configuration"
+    )
+
 # --- Prolog that will be included at the top of every rst file
 # Here: defining the role :red: for html and latex
 rst_prolog = r"""

diff --git a/docs/requirements.txt b/docs/requirements.txt
@@ -5,7 +5,7 @@ pyparsing>=2.1
 Sphinx>=1.8.5
 sphinxcontrib-bibtex>=2.0.0
 sphinxcontrib-doxylink>=1.3
-sphinxcontrib-mermaid>=0.6
+sphinxcontrib-mermaid>=2.1
 sphinx_rtd_theme>=0.3
 requests[security]
 urllib3<2.0.0
diff --git a/docs/source/user/aerodyn/driver.rst b/docs/source/user/aerodyn/driver.rst
@@ -161,6 +161,20 @@ Yawing occurs around the :math:`z_n` axis,  the rotor rotates about the :math:`x
 
 **Turbine geometry definition**
 
+Each turbine block begins with `BasicHAWTFormat`, selecting between the two
+geometry formats described below, followed by `MirrorRotor`. `MirrorRotor` is
+read for both formats. Setting it to `True` runs the turbine as its mirror
+image, so the rotor turns counter-clockwise viewed from upwind, without changing
+any of the geometry, blade or airfoil inputs that describe it. The driver
+mirrors the prescribed hub motion and blade pitch to match. In the basic HAWT
+format the blade azimuth spacing also carries the rotation sense, so the blades
+are numbered in the direction of rotation and blade k of a mirrored rotor is
+the mirror image of blade k of a clockwise one. The advanced format takes the
+blade azimuths (`BldOrientation_h`) as given, so for a mirrored rotor the user
+supplies the mirrored azimuths themselves. See
+:numref:`glue-code-mirror-rotor` for what the flag does and what it does not
+mirror.
+
 Two turbine input formats are supported:
 
 - basic (`BasicHAWTFormat=True`): Basic horizontal axis wind turbine (HAWT) format.
@@ -178,7 +192,8 @@ Two turbine input formats are supported:
 .. code::
 
     ----- Turbine(1) Geometry -------------------------------------------------------
-            True    BasicHAWTFormat(1) - Flag to switch between basic or generic input format {True: next 7 lines are basic inputs, False: Base/Twr/Nac/Hub/Bld geometry and motion must follow}
+            True    BasicHAWTFormat(1) - Flag to switch between basic or generic input format {True: basic HAWT inputs BaseOriginInit to Twr2Shft, False: Base/Twr/Nac/Hub/Bld geometry and motion must follow}
+           False    MirrorRotor(1)  - Flag indicating the rotor rotation direction is mirrored (counter-clockwise viewed from upwind)
            0,0,0    BaseOriginInit(1) - Coordinates of turbine base in global coordinates (m)
                3    NumBlades(1)    - Number of blades (-)
               3.    HubRad(1)       - Hub radius (m)
@@ -215,7 +230,8 @@ Two turbine input formats are supported:
 .. code::
 
     ----- Turbine(1) Geometry -------------------------------------------------------
-         False      BasicHAWTFormat(1) - Flag to switch between basic or generic input format {True: next 7 lines are basic inputs, False: Base/Twr/Nac/Hub/Bld geometry and motion must follow}
+         False      BasicHAWTFormat(1) - Flag to switch between basic or generic input format {True: basic HAWT inputs BaseOriginInit to Twr2Shft, False: Base/Twr/Nac/Hub/Bld geometry and motion must follow}
+    False           MirrorRotor(1)         - Flag indicating the rotor rotation direction is mirrored (counter-clockwise viewed from upwind)
     0,0,0           BaseOriginInit(1)      - x,y,z coordinates of turbine base origin (m)
     0,0,0           BaseOrientationInit(1) - successive rotations (theta_x, theta_y, theta_z) defining initial orientation of the base frame from the global frame (e.g. roll, tilt, yaw) (deg)
     True            HasTower(1)            - True if turbine has a tower (flag)
@@ -492,7 +508,8 @@ An example of an AeroDyn driver for a basic inflow, basic HAWT, and combined cas
     ----- Turbine Data ----------------------------------------------------------------------
     1               NumTurbines - Number of turbines
     ----- Turbine(1) Geometry ---------------------------------------------------------------
-            True    BasicHAWTFormat(1) - Flag to switch between basic or generic input format {True: next 7 lines are basic inputs, False: Base/Twr/Nac/Hub/Bld geometry and motion must follow}
+            True    BasicHAWTFormat(1) - Flag to switch between basic or generic input format {True: basic HAWT inputs BaseOriginInit to Twr2Shft, False: Base/Twr/Nac/Hub/Bld geometry and motion must follow}
+           False    MirrorRotor(1)  - Flag indicating the rotor rotation direction is mirrored (counter-clockwise viewed from upwind)
            0,0,0    BaseOriginInit(1) - Coordinate of tower base in base coordinates (m)
                3    NumBlades(1)    - Number of blades (-)
               3.    HubRad(1)       - Hub radius (m)

diff --git a/docs/source/user/aerodyn/examples/ad_driver_example.dvr b/docs/source/user/aerodyn/examples/ad_driver_example.dvr
@@ -26,7 +26,8 @@ False           Echo         - Echo input parameters to "<rootname>.ech"?
 ----- Turbine Data ----------------------------------------------------------------------
 1               NumTurbines  - Number of turbines
 ----- Turbine(1) Geometry ---------------------------------------------------------------
-        True    BasicHAWTFormat(1) - Flag to switch between basic or generic input format {True: next 7 lines are basic inputs, False: Base/Twr/Nac/Hub/Bld geometry and motion must follow}
+        True    BasicHAWTFormat(1) - Flag to switch between basic or generic input format {True: basic HAWT inputs BaseOriginInit to Twr2Shft, False: Base/Twr/Nac/Hub/Bld geometry and motion must follow}
+False           MirrorRotor(1) - Flag indicating the rotor rotation direction is mirrored (counter-clockwise viewed from upwind)
        0,0,0    BaseOriginInit(1) - Coordinate of tower base in base coordinates (m)
            3    NumBlades(1)    - Number of blades (-)
           3.    HubRad(1)       - Hub radius (m)

diff --git a/docs/source/user/aerodyn/examples/ad_driver_multiple.dvr b/docs/source/user/aerodyn/examples/ad_driver_multiple.dvr
@@ -26,7 +26,8 @@ False           Echo        - Echo input parameters to "<rootname>.ech"?
 ----- Turbine Data ----------------------------------------------------------------------
 2               NumTurbines - Number of turbines
 ----- Turbine(1) ------------------------------------------------------------------------
-     False      BasicHAWTFormat(1) - Flag to switch between basic or generic input format {True: next 7 lines are basic inputs, False: Base/Twr/Nac/Hub/Bld geometry and motion must follow}
+     False      BasicHAWTFormat(1) - Flag to switch between basic or generic input format {True: basic HAWT inputs BaseOriginInit to Twr2Shft, False: Base/Twr/Nac/Hub/Bld geometry and motion must follow}
+False           MirrorRotor(1) - Flag indicating the rotor rotation direction is mirrored (counter-clockwise viewed from upwind)
 00,00,00        BaseOriginInit(1)      - x,y,z coordinates of base origin (m)
 0,0,0           BaseOrientationInit(1) - successive rotations (theta_x, theta_y, theta_z) defining initial orientation of the base frame from the global frame (e.g. roll, tilt, yaw) (deg)
 True            HasTower(1)            - True if turbine has a tower (flag)
@@ -66,7 +67,8 @@ True            HAWTprojection(1)      - True if turbine is a horizontal axis tu
 "unused" BldMotionFileName(1_2)  - Filename containing blade pitch motion [used only when BldMotionType=1]
 "unused" BldMotionFileName(1_3)  - Filename containing blade pitch motion [used only when BldMotionType=1]
 ----- Turbine(2) Geometry ---------------------------------------------------------------
-        True    BasicHAWTFormat(2) - Flag to switch between basic or generic input format {True: next 7 lines are basic inputs, False: Base/Twr/Nac/Hub/Bld geometry and motion must follow}
+        True    BasicHAWTFormat(2) - Flag to switch between basic or generic input format {True: basic HAWT inputs BaseOriginInit to Twr2Shft, False: Base/Twr/Nac/Hub/Bld geometry and motion must follow}
+False           MirrorRotor(2) - Flag indicating the rotor rotation direction is mirrored (counter-clockwise viewed from upwind)
 100,0,0         BaseOriginInit(2) - Coordinate of tower base in base coordinates [used only when HasTower is True] (m)
            3    NumBlades(2)    - Number of blades (-)
         3.      HubRad(2)       - Hub radius (m)

diff --git a/docs/source/user/fast.farm/InputFiles.rst b/docs/source/user/fast.farm/InputFiles.rst
@@ -390,6 +390,13 @@ For each wind turbine:
    :numref:`FF:Input:OFInput` for information on the contents of
    the OpenFAST input files.
 
+   Two OpenFAST features are refused under FAST.Farm at initialization,
+   with a fatal error, rather than run unverified: an OpenFAST model with
+   more than one rotor (**NRotors** > 1 — only one rotor per OpenFAST
+   instance is supported with FAST.Farm), and a mirrored rotor
+   (**MirrorRotor** = True — the wake coupling has not yet been verified
+   for a counter-clockwise rotor; see :numref:`glue-code-mirror-rotor`).
+
 -  When **Mod_AmbWind** = 2 or 3, the Wind Turbines table has six
    additional columns to complete the spatial discretization of the
    high-resolution wind domain for each wind turbine:

diff --git a/docs/source/user/glue-code/index.rst b/docs/source/user/glue-code/index.rst
@@ -15,4 +15,5 @@ the glue code from a user and module-developer perspective.
    modvar
    modglue
    solver
+   mirror_rotor
    linearization
-Original file line number
+Diff line change
@@ Expand Up / @@ -15,4 +15,5 @@ the glue code from a user and module-developer perspective. @@
        modvar
        modglue
        solver
+       mirror_rotor
        linearization