Initial work on #10244: Protection rules (#14097)

docs/configuration/data-validation.md

@@ -87,3 +87,24 @@ The following colors are supported:
 * `gray`
 * `black`
 * `white`
+
+---
+
+## PROTECTION_RULES
+
+!!! tip "Dynamic Configuration Parameter"
+
+This is a mapping of models to [custom validators](../customization/custom-validation.md) against which an object is evaluated immediately prior to its deletion. If validation fails, the object is not deleted. An example is provided below:
+
+```python
+PROTECTION_RULES = {
+    "dcim.site": [
+        {
+            "status": {
+                "eq": "decommissioning"
+            }
+        },
+        "my_plugin.validators.Validator1",
+    ]
+}
+```

docs/customization/custom-validation.md

@@ -26,6 +26,8 @@ The `CustomValidator` class supports several validation types:
 * `regex`: Application of a [regular expression](https://en.wikipedia.org/wiki/Regular_expression)
 * `required`: A value must be specified
 * `prohibited`: A value must _not_ be specified
+* `eq`: A value must be equal to the specified value
+* `neq`: A value must _not_ be equal to the specified value
 
 The `min` and `max` types should be defined for numeric values, whereas `min_length`, `max_length`, and `regex` are suitable for character strings (text values). The `required` and `prohibited` validators may be used for any field, and should be passed a value of `True`.