[in] A string type variable containing the property value.
true success, otherwise false. To get information about the error, call the GetLastError() function.
The minute and tick history of the custom symbol is completely removed if the SYMBOL_FORMULA property (setting the equation for the custom symbol price construction) is changed in the symbol specification. After deleting the custom symbol history, the terminal attempts to create a new history using the new equation. The same happens when the custom symbol equation is changed manually.