To create a smart leader you need to use the standard command MLeader (MLD), specify the insertion point and leave the text empty. This will signal the program that you need to mark the leader as "smart" and start finding objects under the arrow. As the same signal you can enter the text ‘?’ or letter ‘n’ (from ‘name’ word) or any text with one of the substitutions, enclosed in percent symbols ’%’. After that, the leader will always be considered "smart" and will be updated on command LeaderUpdate.

Note that the intelligence of leaders is not like yours. The leader may find nothing or find not what you expected. If the leader has not found the object, the text will be replaced with the template. To avoid errors the found object is highlighted. 

Please be aware:

• Use only one of the topmost objects. Hidden under it are not taken into account. But you can turn on the search option "Many objects"

• In the usual mode, you can (and need to) put the leader in the center of the surfaces of solids, where there are no edges. Even if Autodesk® AutoCAD® does not display the surface (the wireframe mode), the program will still find a solid.

• If the program is configured to find inside blocks, but the inner object has no name (or other specified parameter), then the leader will display the block name.

• Measurement of the solid follows the same rules as the program Sawing Table: measured dimensions of the smallest box which will fit it solid. You can mark the solid as the sweep (A>V>C> Properties Palette plugin required).

• When you change the drawing, the content of the leader itself will not change. Use the LeaderUpdate or AVCUpdate command to update smart leaders.

• A multileader can have a few arrows, but for finding objects use only first one. If you are adding arrows to the leader, the object will be searched under the first (oldest) arrow. When you delete the first arrow the program will look for the object under the remaining arrow..

• Nothing is impossible to find on the view made by the ViewBase command. The fact is that such views do not reflect your details, but a special hidden block. Therefore, for using Smart Leaders use viewports on layouts, but not ViewBase.

• Special leaders of the Autodesk® AutoCAD® Mechanical add-on do not grow wiser either. I strongly do not recommend using A>V>C> plug-in in conjunction with AutoCAD Mechanical.

The program can display many properties of objects found under the arrow of the leader. To select the properties you need, use substitutions. Standard substitutions are described here. If the program does not find the standard substitution, it will look for a block attribute with that name or dynamic block parameter. All substitutions are written only in small letters. And attributes of blocks should be written in the same register as they are written in the block.

Follow the messages on the console. There may be program messages.

The installer that ran when you downloaded this app/plug-in from the Autodesk App Store will start installing the app/plug-in. OR, simply double-click the downloaded installer to install the app/plugin. You may need to restart the Autodesk product to activate the app/plug-in. To uninstall this plug-in, exit the Autodesk product if you are currently running it, simply rerun the installer, and select the "Uninstall" button. OR, click Control Panel > Programs > Programs and Features (Windows 7/8.1/10/11) and uninstall as you would any other application from your system. 

Please read FAQ if any problem

Uninstallation

To uninstall this plug-in just delete the folder AVC_Leader.bundle. After uninstalling you can delete the Windows registry key «CU\Software\AVC\AVC_Leader»

Native search method

• If you copy smart leader by _Copy command then automatically update only the first copy. Other copies can be updated by the command LeaderUpdate 
• I recommend disabling the AutoCAD option "Make new dimensions associative" (system variable DIMASSOC should put 1 instead of 2) because when it is enabled, leaders behave unpredictably. It has nothing to do with the work of my plugin. 
• When you display the sizes of objects inside the blocks, the block scale is NOT taken into account. If you call _Scale for a block or change the ScaleX property of the block, all the dimensions of the parts inside the block will remain old! Unit Factor is also not taken into account.
• There are features and limitations to the use of fields in leadres. 
• Notes and symbols AutoCAD Mechanical knows how to disable their visibility and therefore tightly close the objects. (The problem occurs when using the native search method).
• One user encountered damage to DWG files by using Smart Leaders in Mechanical 2017. I strongly do not recommend using my plug-in with the AutoCAD Mechanical add-in.