diff --git a/libethcore/ICAP.h b/libethcore/ICAP.h
index 60003a1f9..7d5ce1f51 100644
--- a/libethcore/ICAP.h
+++ b/libethcore/ICAP.h
@@ -37,15 +37,23 @@ namespace eth
 
 struct InvalidICAP: virtual public dev::Exception {};
 
+static const std::string EmptyString;
+
 class ICAP
 {
 public:
+	/// Construct null ICAP object.
 	ICAP() = default;
-	ICAP(Address const& _a): m_direct(_a) {}
+	/// Construct a direct ICAP object for given target address. Must have a zero first byte.
+	ICAP(Address const& _target): m_direct(_target) {}
+	/// Construct an indirect ICAP object for given target name.
 	ICAP(std::string const& _target): m_client(_target), m_asset("ETH") {}
+	/// Construct an indirect ICAP object for given client and institution names.
 	ICAP(std::string const& _client, std::string const& _inst): m_client(_client), m_institution(_inst), m_asset("XET") {}
+	/// Construct an indirect ICAP object for given client, institution and asset names. You generally don't want to use this.
 	ICAP(std::string const& _c, std::string const& _i, std::string const& _a): m_client(_c), m_institution(_i), m_asset(_a) {}
 
+	/// Type of ICAP address.
 	enum Type
 	{
 		Invalid,
@@ -53,16 +61,33 @@ public:
 		Indirect
 	};
 
+	/// @returns IBAN encoding of client and data.
 	static std::string iban(std::string _c, std::string _d);
+	/// @returns Client and data from given IBAN address.
 	static std::pair<std::string, std::string> fromIBAN(std::string _iban);
 
+	/// @returns the ICAP object for the ICAP address given.
 	static ICAP decoded(std::string const& _encoded);
+
+	/// @returns the encoded ICAP address.
 	std::string encoded() const;
+	/// @returns type of ICAP.
 	Type type() const { return m_type; }
+	/// @returns target address. Only valid when type() == Direct.
+	Address const& direct() const { return m_type == Direct ? m_direct : Address(); }
+	/// @returns asset. Only valid when type() == Indirect.
+	std::string const& asset() const { return m_type == Indirect ? m_asset : EmptyString; }
+	/// @returns target name. Only valid when type() == Indirect and asset() == "ETH".
+	std::string const& target() const { return m_type == Indirect && m_asset == "ETH" ? m_client : EmptyString; }
+	/// @returns institution name. Only valid when type() == Indirect and asset() == "XET".
+	std::string const& institution() const { return m_type == Indirect && m_asset == "XET" ? m_institution : EmptyString; }
+	/// @returns client name. Only valid when type() == Indirect and asset() == "XET".
+	std::string const& client() const { return m_type == Indirect && m_asset == "XET" ? m_client : EmptyString; }
+	/// @returns target address. Always valid, but requires the Registry address and a function to make calls.
+	Address address(std::function<bytes(Address, bytes)> const& _call, Address const& _reg) const { return m_type == Direct ? direct() : m_type == Indirect ? lookup(_call, _reg) : Address(); }
 
-	Address const& direct() const { return m_direct; }
+	/// @returns target address. Looks up through the given Registry and call function. Only valid when type() == Indirect.
 	Address lookup(std::function<bytes(Address, bytes)> const& _call, Address const& _reg) const;
-	Address address(std::function<bytes(Address, bytes)> const& _call, Address const& _reg) const { return m_type == Direct ? direct() : lookup(_call, _reg); }
 
 private:
 	Type m_type = Invalid;