diff --git a/src/uml/command_parser.cc b/src/uml/command_parser.cc
new file mode 100644
index 00000000..f6b945c6
--- /dev/null
+++ b/src/uml/command_parser.cc
@@ -0,0 +1,143 @@
+/**
+ * src/uml/command_parser.cc
+ *
+ * Copyright (c) 2021 Bartek Kryza <bkryza@gmail.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "command_parser.h"
+
+#include "util/util.h"
+
+#include <string>
+#include <string_view>
+
+namespace clanguml {
+namespace command_parser {
+
+std::shared_ptr<command> command::from_string(std::string_view c)
+{
+    if (c.find("note") == 0) {
+        return note::from_string(c);
+    }
+    else if (c.find("style") == 0) {
+        return style::from_string(c);
+    }
+    else if (c.find("aggregation") == 0) {
+        return aggregation::from_string(c);
+    }
+
+    return {};
+}
+
+std::shared_ptr<command> note::from_string(std::string_view c)
+{
+    auto res = std::make_shared<note>();
+    auto it = c.begin();
+    // Skip 'note'
+    std::advance(it, 4);
+
+    if (*it != '[')
+        return {};
+
+    std::advance(it, 1);
+
+    auto pos = std::distance(c.begin(), it);
+    res->position = c.substr(pos, c.find("]", pos) - pos);
+
+    std::advance(it, res->position.size() + 1);
+
+    pos = std::distance(c.begin(), it);
+    res->text = c.substr(pos, c.find("}", pos) - pos);
+
+    res->position = util::trim(res->position);
+    res->text = util::trim(res->text);
+
+    return res;
+}
+
+std::shared_ptr<command> style::from_string(std::string_view c)
+{
+    auto res = std::make_shared<style>();
+    auto it = c.begin();
+    // Skip 'style'
+    std::advance(it, 5);
+
+    if (*it != '[')
+        return {};
+
+    std::advance(it, 1);
+
+    auto pos = std::distance(c.begin(), it);
+    res->spec = c.substr(pos, c.find("]", pos) - pos);
+
+    res->spec = util::trim(res->spec);
+
+    return res;
+}
+
+std::shared_ptr<command> aggregation::from_string(std::string_view c)
+{
+    auto res = std::make_shared<aggregation>();
+    auto it = c.begin();
+    // Skip 'aggregation'
+    std::advance(it, 11);
+
+    if (*it != '[')
+        return {};
+
+    std::advance(it, 1);
+
+    auto pos = std::distance(c.begin(), it);
+    res->multiplicity = c.substr(pos, c.find("]", pos) - pos);
+
+    res->multiplicity = util::trim(res->multiplicity);
+
+    return res;
+}
+
+std::vector<std::shared_ptr<command>> parse(std::string documentation_block)
+{
+    std::vector<std::shared_ptr<command>> res;
+    const std::string begin_tag{"@clanguml"};
+    const auto begin_tag_size = begin_tag.size();
+
+    // First replace all \clanguml occurences with @clanguml
+    util::replace_all(documentation_block, "\\clanguml", "@clanguml");
+    documentation_block = util::trim(documentation_block);
+
+    std::string_view block_view{documentation_block};
+
+    auto pos = block_view.find("@clanguml{");
+    while (pos < documentation_block.size()) {
+        auto c_begin = pos + begin_tag_size;
+        auto c_end = documentation_block.find("}", c_begin);
+
+        if (c_end == std::string::npos)
+            return res;
+
+        auto com =
+            command::from_string(block_view.substr(c_begin + 1, c_end - 2));
+
+        if (com)
+            res.emplace_back(std::move(com));
+
+        pos = block_view.find("@clanguml{", c_end);
+    }
+
+    return res;
+};
+
+} // namespace command_parser
+} // namespace clanguml
+
diff --git a/src/uml/command_parser.h b/src/uml/command_parser.h
new file mode 100644
index 00000000..7dce5281
--- /dev/null
+++ b/src/uml/command_parser.h
@@ -0,0 +1,55 @@
+/**
+ * src/uml/command_parser.h
+ *
+ * Copyright (c) 2021 Bartek Kryza <bkryza@gmail.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#pragma once
+
+#include "config/config.h"
+#include <functional>
+#include <map>
+#include <memory>
+#include <string>
+
+namespace clanguml {
+namespace command_parser {
+
+struct command {
+    virtual ~command() = default;
+    static std::shared_ptr<command> from_string(std::string_view c);
+};
+
+struct note : public command {
+    std::string position;
+    std::string text;
+
+    static std::shared_ptr<command> from_string(std::string_view c);
+};
+
+struct style : public command {
+    std::string spec;
+    static std::shared_ptr<command> from_string(std::string_view c);
+};
+
+struct aggregation : public command {
+    std::string multiplicity;
+    static std::shared_ptr<command> from_string(std::string_view c);
+};
+
+std::vector<std::shared_ptr<command>> parse(std::string documentation_block);
+
+} // namespace command_parser
+} // namespace clanguml
+
diff --git a/src/util/util.cc b/src/util/util.cc
index 88133b89..656e4040 100644
--- a/src/util/util.cc
+++ b/src/util/util.cc
@@ -126,5 +126,20 @@ bool find_element_alias(
 
     return true;
 }
+
+bool replace_all(
+    std::string &input, std::string pattern, std::string replace_with)
+{
+    bool replaced{false};
+
+    auto pos = input.find(pattern);
+    while (pos < input.size()) {
+        input.replace(pos, pattern.size(), replace_with);
+        pos = input.find(pattern, pos + replace_with.size());
+        replaced = true;
+    }
+
+    return replaced;
+}
 }
 }
diff --git a/src/util/util.h b/src/util/util.h
index a20fa8e4..3d87acc8 100644
--- a/src/util/util.h
+++ b/src/util/util.h
@@ -104,5 +104,15 @@ std::string unqualify(const std::string &s);
  */
 bool find_element_alias(
     const std::string &input, std::tuple<std::string, size_t, size_t> &result);
+
+/**
+ * @brief Find and replace in string
+ *
+ * Replaces all occurences of pattern with replace_with in input string.
+ *
+ * @return True if at least on replacement was made
+ */
+bool replace_all(
+    std::string &input, std::string pattern, std::string replace_with);
 }
 }
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 26404886..d6c54b88 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -23,6 +23,14 @@ set(CLANG_UML_TEST_CASES_HEADER
     catch.h
 )
 
+set(CLANG_UML_TEST_COMMAND_PARSER_SRC
+    test_command_parser.cc
+    ${TEST_UTIL_SOURCES}
+)
+set(CLANG_UML_TEST_COMMAND_PARSER_HEADER
+    catch.h
+)
+
 add_executable(test_util
     ${CLANG_UML_TEST_UTIL_SRC}
     ${CLANG_UML_TEST_UTIL_HEADER})
@@ -33,6 +41,15 @@ target_link_libraries(test_util
     ${YAML_CPP_LIBRARIES}
     spdlog::spdlog clang-umllib cppast)
 
+add_executable(test_command_parser
+    ${CLANG_UML_TEST_COMMAND_PARSER_SRC}
+    ${CLANG_UML_TEST_COMMAND_PARSER_HEADER})
+
+target_link_libraries(test_command_parser
+    PRIVATE
+    ${LIBCLANG_LIBRARIES}
+    ${YAML_CPP_LIBRARIES}
+    spdlog::spdlog clang-umllib cppast)
 
 add_executable(test_cases
     ${CLANG_UML_TEST_CASES_SRC}
@@ -57,4 +74,5 @@ foreach(TEST_CASE_CONFIG ${TEST_CASE_CONFIGS})
 endforeach()
 
 add_test(NAME test_util COMMAND test_util)
+add_test(NAME test_command_parser COMMAND test_command_parser)
 add_test(NAME test_cases COMMAND test_cases)
diff --git a/tests/test_command_parser.cc b/tests/test_command_parser.cc
new file mode 100644
index 00000000..22650441
--- /dev/null
+++ b/tests/test_command_parser.cc
@@ -0,0 +1,113 @@
+/**
+ * tests/test_command_parser.cc
+ *
+ * Copyright (c) 2021 Bartek Kryza <bkryza@gmail.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#define CATCH_CONFIG_MAIN
+
+#include "uml/command_parser.h"
+
+#include "catch.h"
+
+TEST_CASE("Test command parser on regular comment", "[unit-test]")
+{
+    std::string comment = R"(
+    \brief This is a comment.
+
+    This is a longer comment.
+
+    \param a int an int
+    \param b float a float
+
+    )";
+
+    using namespace clanguml::command_parser;
+
+    auto commands = parse(comment);
+
+    CHECK(commands.empty());
+}
+
+TEST_CASE("Test command parser on note", "[unit-test]")
+{
+    std::string comment = R"(
+    \brief This is a comment.
+
+    This is a longer comment.
+
+    \
+
+    \param a int an int
+    \param b float a float
+
+    \clanguml{note[left] This is a comment}
+    @clanguml{note[ top  ]
+
+            This is a comment    }
+    )";
+
+    using namespace clanguml::command_parser;
+
+    auto commands = parse(comment);
+
+    CHECK(commands.size() == 2);
+
+    auto n1 = std::dynamic_pointer_cast<note>(commands.at(0));
+    auto n2 = std::dynamic_pointer_cast<note>(commands.at(1));
+
+    CHECK(n1);
+    CHECK(n1->position == "left");
+    CHECK(n1->text == "This is a comment");
+
+    CHECK(n2);
+    CHECK(n2->position == "top");
+    CHECK(n2->text == "This is a comment");
+}
+
+TEST_CASE("Test command parser on style", "[unit-test]")
+{
+    std::string comment = R"(
+    \clanguml{style[#green,dashed,thickness=4]}
+    )";
+
+    using namespace clanguml::command_parser;
+
+    auto commands = parse(comment);
+
+    CHECK(commands.size() == 1);
+
+    auto n1 = std::dynamic_pointer_cast<style>(commands.at(0));
+
+    CHECK(n1);
+    CHECK(n1->spec == "#green,dashed,thickness=4");
+}
+
+TEST_CASE("Test command parser on aggregation", "[unit-test]")
+{
+    std::string comment = R"(
+    \clanguml{aggregation[0..1:0..*]}
+    )";
+
+    using namespace clanguml::command_parser;
+
+    auto commands = parse(comment);
+
+    CHECK(commands.size() == 1);
+
+    auto n1 = std::dynamic_pointer_cast<aggregation>(commands.at(0));
+
+    CHECK(n1);
+    CHECK(n1->multiplicity == "0..1:0..*");
+}
diff --git a/tests/test_util.cc b/tests/test_util.cc
index 1cd75d0f..80c102c0 100644
--- a/tests/test_util.cc
+++ b/tests/test_util.cc
@@ -46,3 +46,25 @@ TEST_CASE("Test ns_relative", "[unit-test]")
         "static const vector<a>&");
     CHECK(ns_relative({"clanguml::t0"}, "clanguml::t0") == "t0");
 }
+
+TEST_CASE("Test replace_all", "[unit-test]")
+{
+    using namespace clanguml::util;
+
+    const std::string orig = R"(
+                        Lorem ipsum \clanguml{note} something something...
+
+                        \clanguml{style}
+
+                        )";
+    std::string text{orig};
+
+    CHECK(replace_all(text, "NOTHERE", "HERE") == false);
+    CHECK(replace_all(text, "\\clanguml", "@clanguml") == true);
+    CHECK(replace_all(text, "something", "nothing") == true);
+    CHECK(replace_all(text, "something", "nothing") == false);
+    CHECK(replace_all(text, "nothing", "something") == true);
+    CHECK(replace_all(text, "@clanguml", "\\clanguml") == true);
+
+    CHECK(text == orig);
+}