diff --git a/database/__init__.py b/database/__init__.py
new file mode 100644
index 0000000..06d7405
Binary files /dev/null and b/database/__init__.py differ
diff --git a/database/fields.py b/database/fields.py
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--- /dev/null
+++ b/database/fields.py
@@ -0,0 +1,12 @@
+import re
+from mongoengine import StringField
+
+
+class RegexField(StringField):
+    def __init__(self, regex, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.regex = re.compile(regex)
+
+    def validate(self, value, clean=True):
+        if not self.regex.fullmatch(value):
+            self.error('The given string does not match the regex for this field')