diff --git a/docs/source_docs/user_guide/inputs/mesh_and_gridding.rst b/docs/source_docs/user_guide/inputs/mesh_and_gridding.rst
index 1a33bd56494ad4957a1a0fb91d3c52fa5d159c3c..5f30221bd9871f7df577a824726e652afd0443a4 100644
--- a/docs/source_docs/user_guide/inputs/mesh_and_gridding.rst
+++ b/docs/source_docs/user_guide/inputs/mesh_and_gridding.rst
@@ -98,6 +98,69 @@ mesh refinement algorithm and are only applicable when ``amr.max_level > 0``.
 See the `AMReX documentation <https://amrex-codes.github.io/amrex/docs_html/index.html>`_
 for details on the adaptive mesh refinement algorithms.
 
+The following inputs are defined using the prefix ``mfix.tag``. They control how cells are tagged
+for the mesh refinement algorithm and are only applicable when ``amr.max_level > 0``.
+
+Cells intersected by the embedded boundary are always tagged for refinement, regardless of these settings.
+
++----------------------+-----------------------------------------------------------------------+-------------+-----------+
+|                      | Description                                                           |   Type      | Default   |
++======================+=======================================================================+=============+===========+
+| rho                  | Tag cells for refinement when the fluid density is **greater than**   |    Reals    |  None     |
+|                      | the specified value.                                                  |             |           |
+|                      |                                                                       |             |           |
+|                      | * To tag cells when density is **less than** the specified value,     |             |           |
+|                      |   set ``mfix.rho.less_than = true``.                                  |             |           |
+|                      | * Values may be specified per level. If fewer than ``amr.max_level``  |             |           |
+|                      |   values are provided, the last value is used for all higher levels.  |             |           |
++----------------------+-----------------------------------------------------------------------+-------------+-----------+
+| rho.less_than        | Tag cells for refinement when the fluid density is **less than** the  |    Bool     |  false    |
+|                      | specified value.                                                      |             |           |
++----------------------+-----------------------------------------------------------------------+-------------+-----------+
+| grad_rho             | Tag cells for refinement when the difference in fluid density between |    Reals    |  None     |
+|                      | two adjacent cells is greater than the specified value.               |             |           |
+|                      |                                                                       |             |           |
+|                      | * To tag cells when the difference is less than the specified value,  |             |           |
+|                      |   set ``mfix.grad_rho.less_than = true``.                             |             |           |
+|                      | * Values may be specified per level. If fewer than ``amr.max_level``  |             |           |
+|                      |   values are provided, the last value is used for all higher levels.  |             |           |
++----------------------+-----------------------------------------------------------------------+-------------+-----------+
+| grad_rho.less_than   | Tag cells for refinement when the difference in fluid density between |    Bool     |  false    |
+|                      | two adjacent cells is **less than** the specified value.              |             |           |
++----------------------+-----------------------------------------------------------------------+-------------+-----------+
+| vel                  | Tag cells for refinement when the difference in any fluid velocity    |    Reals    |  None     |
+|                      | component between two adjacent cells is **greater than** the          |             |           |
+|                      | specified value.                                                      |             |           |
+|                      |                                                                       |             |           |
+|                      | * To tag cells when the difference is less than the specified value,  |             |           |
+|                      |   set ``mfix.grad_vel.less_than = true``.                             |             |           |
+|                      | * Values may be specified per level. If fewer than ``amr.max_level``  |             |           |
+|                      |   values are provided, the last value is used for all higher levels.  |             |           |
+|                      |                                                                       |             |           |
+|                      | Tag cells for refinement when the fluid velocity magnitude is         |             |           |
+|                      | *greater than* the specified value.                                   |             |           |
++----------------------+-----------------------------------------------------------------------+-------------+-----------+
+| vel.less_than        | Tag cells for refinement when fluid velocity magnitude is             |    Bool     |  false    |
+|                      | **less than** the specified value.                                    |             |           |
++----------------------+-----------------------------------------------------------------------+-------------+-----------+
+| grad_vel             | Tag cells for refinement when the difference in any fluid velocity    |    Reals    |  None     |
+|                      | component between two adjacent cells is **greater than** the          |             |           |
+|                      | specified value.                                                      |             |           |
+|                      |                                                                       |             |           |
+|                      | * To tag cells when the difference is less than the specified value,  |             |           |
+|                      |   set ``mfix.grad_vel.less_than = true``.                             |             |           |
+|                      | * Values may be specified per level. If fewer than ``amr.max_level``  |             |           |
+|                      |   values are provided, the last value is used for all higher levels.  |             |           |
++----------------------+-----------------------------------------------------------------------+-------------+-----------+
+| grad_vel.less_than   | Tag cells for refinement when the difference in any fluid velocity    |    Bool     |  false    |
+|                      | component between two adjacent cells is **less than** the specified   |             |           |
+|                      | value.                                                                |             |           |
++----------------------+-----------------------------------------------------------------------+-------------+-----------+
+| regions              | A list of predefined regions used to identify sections of the domain  |   Strings   | None      |
+|                      | for mesh refinement.                                                  |             |           |
++----------------------+-----------------------------------------------------------------------+-------------+-----------+
+
+
 -----
 
 Grids