I need to know if given package exists or not. Currently found two solution - one doesn't work, another works but I don't like it.   **Solution 1.** I started, of course, with %Dictionary package - it has PackageDefinition class after all. However, %ExistsId returned on packages that clearly do exist, so I went to %LoadData, it uses this macro to determine if the package exist: #define PACKAGE(%package) ^oddPKG($zcvt(%package,"u")) And zw ^oddPKG showed the root cause - ^oddPKG global only contains data for packages with tables (or something along these lines).   **Solution 2.** Using sql to find first class that starts with package name. Seems like an overhead to me. Query PackageExists(package) As %SQLQuery { SELECT TOP 1 1 As "Exists" FROM %Dictionary.ClassDefinition WHERE ID %STARTSWITH :package } /// write ##class().GetPackageExists("isc") ClassMethod GetPackageExists(class) { #dim exists As %Boolean if class = "" { set exists = $$$YES } else { set package = $case($l(class, "."), 1: class, : $p(class, ".", 1, *-1)) set rs = ..PackageExistsFunc(package) do rs.%Next() set exists = (rs.Exists = $$$YES) } quit exists } Ideas?