In this article we will create Line based Details component that has text embedded into the line. These lines you can use to show different services as example. Similar to the screenshot below.

The first step is to create a Family.

Then select the Line Based Detail Component Family template.

In the empty family click Create ribbon -> Line.

Make sure the Line tool is selected and then select the Light Line. Draw the line in the drawing area from the left intersection to the right intersection as shown.

Now to add the text item we’ll create an Annotation symbol and load it into the Line based family. To start go New -> Annotation symbol.

Select the Generic Annotation template.

In the drawing area click Create tab and Label. Click close to the intersection to place the Label.

In the resulting Edit Label Dialogue box click create at the bottom. Name the parameter. Set its type to Text and click Ok.

Once the parameter is created in Revit click the green arrow to add it to the Label.

You’ll see the Label being added to the intersection. Now delete the red text and Save the file.

Load the Family into the Line Based Detail component.

Back in the Line Based Family. Add the Annotation Symbol by clicking Create -> Symbol.

Place the text symbol in your drawing area as shown. We’ll later position it correctly.

To create some detail wrt left and right insets create two vertical Reference Planes as shown.

Add a dimensions to each of the reference planes.

Select the first of the dimensions and click Add Parameter as shown.

In the following dialogue box name the parameter and click OK.

Now that the Parameter is created you can select the other dim and pick the parameter from the list.

Now that the insets are created we need to set up the positions of the inserted Letter parameter. Select the Question Mark family -> Click Array and make sure you have Last option selected. I also set the Number of items to 4.

This will create 4 items. Select the leftmost one and Align and lock it to the horizontal reference plane at the inset. Also Align and Lock to the vertical reference plane.

Align and Lock the rightmost question mark item. To the right inset.

Good idea is now to test your family by clicking the Family Types icon. Change the values and see if the family acts according you what you expect.

Now you can create a parameter to set the number of item along the line you would select the array and click Add Parameter.

Name the parameter as shown and click OK.

Test the parameter and see if the number of items change by clicking the Family Type icon and setting the value.

To add actual letters instead of the question mark you can Tab-Select one of the question marks.  Click Edit Type on the Properties palette on the left. Click the small grey map button on the right side of the parameter called Letter in this case. Click Add parameter as shown below.

Name the parameter Letter as well and click Ok. Once created select that same parameter in the Associate Family Parameter box and click Ok.

This operation will map the nested Annotation Symbol parameter called Letter to the parameter called Letter in the Line Based Detail Component.

Save the Detail component Family and Load into your Project.

Draw the line based item using Detail component tool in Annotate Tab-> Detail Panel -> Component.

Now select the line and click Edit Type. Set the Letter to A and click Ok. All the lines that were drawn will now have a A.

You can Edit Type and Duplicate the Family if you require different lettered lines.