By default, PEM Editor uses Hungarian notation for property names, where the first letter is lower case representing the data type of the property.
If this is not the behavior you desire, you can use or modify a Plug-In PRG. Copy GetDefaultValue.PRG from the 'Sample Plug-Ins' folde to the 'Live Plug-Ins' folder. This PRG uses the second letter of the property name to determine the data type. If that is not what is desired either, modify the PRG as necessary to fit your needs.
Finally -- if you always want your new properties to be assigned a default value of .F., de-select the option on the Preferences Form ('General' tab / 'Processing' sub-tab)