diff --git a/include/version.h b/include/version.h
index 7c165b5..fed2982 100644
--- a/include/version.h
+++ b/include/version.h
@@ -29,24 +29,55 @@ SOFTWARE.
 
 namespace version {
 
-	enum class Identifier_type { alnum, num };
+	/// Type of prerelease identifier: alphanumeric or numeric.
+	/**
+	Type of identifier affects comparison: alphanumeric identifiers are compared as ASCII strings, while
+	numeric identifiers are compared as numbers.
+	*/
+	enum class Identifier_type {
+		alnum, ///< Identifier is alphanumerical
+		num ///< Identifier is numeric
+	};
 
+	/// Container for prerelease identifier value and it's type.
+	/**
+	Prerelease version string consist of an optional series of dot-separated identifiers.
+	These identifiers can be either numerical or alphanumerical.
+	This structure describes one such identifier.
+	*/
 	using Prerelease_identifier = std::pair<std::string, Identifier_type>;
+
+	/// Container for all prerelease identifiers for a given version string.
 	using Prerelease_identifiers = std::vector<Prerelease_identifier>;
+
+	/// Build identifier is just a string and has no meaning for the purpose of version precedence.
 	using Build_identifier = std::string;
+
+	/// Container for all build identifiers for a given version string.
 	using Build_identifiers = std::vector<Build_identifier>;
 
+	/// Description of version broken into parts, as per semantic versioning specification.
 	struct Version_data {
-		int major;
-		int minor;
-		int patch;
+		int major; ///< Major version, change only on incompatible API modifications
+		int minor; ///< Minor version, change on compatible API modifications
+		int patch; ///< Patch version, change only on bugfixes
+
+		/// Optional series of prerelease identifiers.
 		Prerelease_identifiers prerelease_ids;
+
+		/// Optional series of build identifiers.
 		Build_identifiers build_ids;
 	};
 
+	/// Generic version class. Specializations are used to perform usefull work.
+	/**
+	This class describes general version object without prescribing parsing, validation and comparison rules.
+	These rules are contained in Parser and Comparator objects provided.
+	*/
 	template<typename Parser, typename Comparator>
 	class Basic_version {
 	public:
+		/// Construct Basic_version object using Parser to parse version string and Comparator for comparison.
 		Basic_version(const std::string&, Parser, Comparator);
 
 		bool operator>(const Basic_version&);
@@ -62,16 +93,20 @@ namespace version {
 		const Version_data ver_;
 	};
 
+	/// Parse string into Version_data structure according to semantic versioning 2.0.0 rules.
 	struct Semver200_parser {
 		Version_data parse(const std::string&);
 	};
 
+	/// Compare Version_data to another using semantic versioning 2.0.0 rules.
 	struct Semver200_comparator {
 		int compare(const Version_data&, const Version_data&);
 	};
 
+	/// Concrete Basic_version class that binds all semver 2.0.0 functionality together.
 	class Semver200 : public Basic_version<Semver200_parser, Semver200_comparator> {};
 
+	/// Parse_error is thrown on all parsing and validation errors.
 	class Parse_error : public std::runtime_error {
 		using std::runtime_error::runtime_error;
 	};
diff --git a/src/Semver200_parser.cpp b/src/Semver200_parser.cpp
index 453d029..045fa8f 100644
--- a/src/Semver200_parser.cpp
+++ b/src/Semver200_parser.cpp
@@ -23,7 +23,6 @@ SOFTWARE.
 */
 
 #include <functional>
-#include <vector>
 #include "version.h"
 
 using namespace std;