diff --git a/include/fractal.hpp b/include/fractal.hpp
index 7042394..cec7352 100644
--- a/include/fractal.hpp
+++ b/include/fractal.hpp
@@ -219,7 +219,9 @@ public:
 	 *
 	 * @ret @c true if the number of mark rules in the ruleset equals @c g_max_mark_rules, @c false otherwise
 	 */
-	bool mark_rules_full() const;
+	bool mark_rules_full() const {
+		return m_mark_rules.full();
+	}
 
 	/** @brief Add a new marking rule to the ruleset
 	 *
diff --git a/src/fractal.cpp b/src/fractal.cpp
index 830881a..f314216 100644
--- a/src/fractal.cpp
+++ b/src/fractal.cpp
@@ -96,6 +96,20 @@ branch_rule_id_t ruleset_t::add_branch_rule_weighted(token_id_t match, weighted_
 	return m_branch_rules.size() - 1;
 }
 
+mark_rule_id_t ruleset_t::add_mark_rule(token_id_t match, uint32_t tag) {
+	if (!valid_token(match)) {
+		throw mtl::invalid_argument();
+	}
+
+	mark_rule_t rule {
+		.m_match = match,
+		.m_tag = tag
+	};
+
+	m_mark_rules.push_back(rule);
+	return m_mark_rules.size() - 1;
+}
+
 #if 0
 token_id_t generator_t::add_token(token_type_e type, mtl::fixed value) {
 	log::debug << "Adding token with type " << (int)type << endl;