There might be circumstances where the presence of a certain subdocument should be conditional. A good example would be the presence of a certain clause in the main body of the agreement. In order to achieve that, follow the three steps outlined below.
1. Create a binder
The first step is to make a binder with all the subdocuments. A new binder is created by clicking on 
and holding shift at the same time. All the subdocuments need to be added to that binder. In order to do so, navigate to the binder pane and add an existing or a new document. Note that one of the files needs to be chosen as the main body.
2. Create a cross-reference
Next, a cross-reference needs to be inserted into the clause upon which the condition will depend. This can be done by either using cross-tags or by implementing concepts, with each of those methods having their own perks. For the purpose of this “how-to”, the cross-tag method will be used.
For a more detailed overview of cross-references, please consult this article and this How To.
This step can of course be skipped if you want the subdocument to be made subject to another type of condition (e.g. to some input in a datafield).
3. Make subdocument conditional
Lastly, the condition needs to be inserted into the subdocument. Navigate to binder > properties and under 
click on the subdocument that shall be conditional.
This is where the properties of the subdocument are changed. In the enabled? pane, the file can be enabled or disabled based on a certain condition. For the purposes of our example, we could say the subdocument should only be enabled if the previously chosen cross-tag has been implemented. Thus, we need to use the special function @crosstag-implemented and insert @crosstag-implemented('cross-tag-name')
Conditions can also be combined by inserting AND or OR followed by a second condition.