diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3ebfa3fb..63499225 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,8 +2,8 @@ cmake_minimum_required(VERSION 3.0)
 cmake_policy(SET CMP0017 NEW) # need include() with .cmake
 project(pip)
 set(pip_MAJOR    2)
-set(pip_MINOR    14)
-set(pip_REVISION 2)
+set(pip_MINOR    15)
+set(pip_REVISION 0)
 set(pip_SUFFIX   )
 set(pip_COMPANY  SHS)
 set(pip_DOMAIN   org.SHS)
diff --git a/libs/main/core/pipropertystorage.cpp b/libs/main/core/pipropertystorage.cpp
index 679d374b..246ba6c9 100644
--- a/libs/main/core/pipropertystorage.cpp
+++ b/libs/main/core/pipropertystorage.cpp
@@ -28,41 +28,54 @@ bool PIPropertyStorage::isPropertyExists(const PIString & _name) const {
 }
 
 
-void PIPropertyStorage::addProperty(const PIPropertyStorage::Property & p) {
+bool PIPropertyStorage::addProperty(const PIPropertyStorage::Property & p) {
 	for (uint i = 0; i < props.size(); ++i)
 		if (props[i].name == p.name) {
 			props[i] = p;
-			return;
+			return false;
 		}
 	props << p;
+	return true;
 }
 
 
-void PIPropertyStorage::addProperty(PIPropertyStorage::Property && p) {
+bool PIPropertyStorage::addProperty(PIPropertyStorage::Property && p) {
 	for (uint i = 0; i < props.size(); ++i)
 		if (props[i].name == p.name) {
 			props[i] = std::move(p);
-			return;
+			return false;
 		}
 	props << std::move(p);
+	return true;
 }
 
 
-void PIPropertyStorage::removeProperty(const PIString & _name) {
-	for (uint i = 0; i < props.size(); ++i)
+bool PIPropertyStorage::addProperty(const PIString & _name, const PIVariant & _def_value, const PIString & _comment, int _flags) {
+	return addProperty(Property(_name, _comment, _def_value, _flags));
+}
+
+
+bool PIPropertyStorage::removeProperty(const PIString & _name) {
+	for (uint i = 0; i < props.size(); ++i) {
 		if (props[i].name == _name) {
 			props.remove(i);
-			return;
+			return true;
 		}
+	}
+	return false;
 }
 
 
-void PIPropertyStorage::removePropertiesByFlag(int flag) {
-	for (int i = 0; i < props.size_s(); ++i)
+int PIPropertyStorage::removePropertiesByFlag(int flag) {
+	int ret = 0;
+	for (int i = 0; i < props.size_s(); ++i) {
 		if ((props[i].flags & flag) == flag) {
 			props.remove(i);
 			--i;
+			ret++;
 		}
+	}
+	return ret;
 }
 
 
@@ -99,30 +112,36 @@ PIVariant PIPropertyStorage::propertyValueByName(const PIString & name) const {
 }
 
 
-void PIPropertyStorage::setPropertyValue(const PIString & name, const PIVariant & value) {
-	for (uint i = 0; i < props.size(); ++i)
+bool PIPropertyStorage::setPropertyValue(const PIString & name, const PIVariant & value) {
+	for (uint i = 0; i < props.size(); ++i) {
 		if (props[i].name == name) {
 			props[i].value = value;
-			return;
+			return true;
 		}
+	}
+	return false;
 }
 
 
-void PIPropertyStorage::setPropertyComment(const PIString & name, const PIString & comment) {
-	for (uint i = 0; i < props.size(); ++i)
+bool PIPropertyStorage::setPropertyComment(const PIString & name, const PIString & comment) {
+	for (uint i = 0; i < props.size(); ++i) {
 		if (props[i].name == name) {
 			props[i].comment = comment;
-			return;
+			return true;
 		}
+	}
+	return false;
 }
 
 
-void PIPropertyStorage::setPropertyFlags(const PIString & name, int flags) {
-	for (uint i = 0; i < props.size(); ++i)
+bool PIPropertyStorage::setPropertyFlags(const PIString & name, int flags) {
+	for (uint i = 0; i < props.size(); ++i) {
 		if (props[i].name == name) {
 			props[i].flags = flags;
-			return;
+			return true;
 		}
+	}
+	return false;
 }
 
 
diff --git a/libs/main/core/pipropertystorage.h b/libs/main/core/pipropertystorage.h
index 9dc4098c..31f01cd3 100644
--- a/libs/main/core/pipropertystorage.h
+++ b/libs/main/core/pipropertystorage.h
@@ -110,24 +110,49 @@ public:
 	PIVector<Property> & properties() {return props;}
 	const PIVector<Property> & properties() const {return props;}
 	const PIPropertyStorage & propertyStorage() const {return *this;}
+
+	/**
+	 * @brief Check if property with \a name exists
+	 * @return "true" if property exists
+	 */
 	bool isPropertyExists(const PIString & _name) const;
+
+	/**
+	 * @brief Remove all properties
+	 */
 	void clearProperties() {props.clear();}
 
 	/**
 	 * @brief Add property if name isn't present in storage, otherwrise update existing property with same name.
-	 *
+	 * @return "true" if new property added, else if update existing property return "false"
 	 * @param p to copy in storage
 	 */
-	void addProperty(const Property & p);
-	void addProperty(Property && p);
+	bool addProperty(const Property & p);
+	bool addProperty(Property && p);
 
 	/**
 	 * @brief First of all construct Property with method params. After then add property if name isn't present
 	 * in storage, otherwrise update existing property with same name.
+	 * @return "true" if new property added, else if update existing property return "false"
+	 */
+	bool addProperty(const PIString & _name, const PIVariant & _def_value, const PIString & _comment = PIString(), int _flags = 0);
+
+	/**
+	 * @brief Remove property with \a name
+	 * @return "true" if property exists and removed
+	 */
+	bool removeProperty(const PIString & _name);
+
+	/**
+	 * @brief Remove properties wich has \a flag set
+	 * @return removed properties count
+	 */
+	int removePropertiesByFlag(int flag);
+
+	/**
+	 * @brief Merge other \a properties_ into this
+	 * @param flag_ignore  - properties wich has this flag set will be ignored in merge
 	 */
-	void addProperty(const PIString & _name, const PIVariant & _def_value, const PIString & _comment = PIString(), int _flags = 0) {addProperty(Property(_name, _comment, _def_value, _flags));}
-	void removeProperty(const PIString & _name);
-	void removePropertiesByFlag(int flag);
 	void updateProperties(const PIVector<Property> & properties_, int flag_ignore = 0);
 
 	/**
@@ -151,24 +176,27 @@ public:
 	 *
 	 * @param name of property to set value
 	 * @param value to set
+	 * @return "true" if property exists and updated
 	 */
-	void setPropertyValue(const PIString & name, const PIVariant & value);
+	bool setPropertyValue(const PIString & name, const PIVariant & value);
 
 	/**
 	 * @brief Set comment of property with specific name if name is present in storage.
 	 *
 	 * @param name of property to set comment
 	 * @param comment to set
+	 * @return "true" if property exists and updated
 	 */
-	void setPropertyComment(const PIString & name, const PIString & comment);
+	bool setPropertyComment(const PIString & name, const PIString & comment);
 
 	/**
 	 * @brief Set flags of property with specific name if name is present in storage.
 	 *
 	 * @param name of property to set flags
 	 * @param flags to set
+	 * @return "true" if property exists and updated
 	 */
-	void setPropertyFlags(const PIString & name, int flags);
+	bool setPropertyFlags(const PIString & name, int flags);
 
 	PIPropertyStorage & operator <<(const PIPropertyStorage::Property & p) {props << p; return *this;}
 	PIPropertyStorage & operator <<(const PIVector<Property> & p) {props << p; return *this;}