Open the airframe project and create a project object.

sldemo_slproject_airframe;
proj = simulinkproject;

Get a particular file by name.

myfile = findFile(proj,'models/AnalogControl.slx')

myfile = 

  ProjectFile with properties:

      Path: 'C:\Work\temp\slexamples\airframe\models\AnalogControl.slx'
    Labels: [1x1 slproject.Label]
  Revision: '2'
SourceControlStatus: Unmodified

Get the Labels property of the file.

myfile.Labels

ans = 

  Label with properties:

            File: 'C:\Work\temp\slexamples\airframe\models\AnalogControl.slx'
            Data: []
        DataType: 'none'
            Name: 'Design'
    CategoryName: 'Classification'

Attach the label 'Artifact' to the file.

addLabel(myfile,'Classification','Artifact')

ans = 

  Label with properties:

            File: 'C:\Work\temp\slexamples\airframe\models\AnalogControl.slx'
            Data: []
        DataType: 'none'
            Name: 'Artifact'
    CategoryName: 'Classification'

Index into the Labels property to get the label attached to this file.

reviewlabel = myfile.Labels(1)

reviewlabel = 

  Label with properties:

            File: 'C:\Work\temp\slexamples\airframe\models\AnalogControl.slx'
            Data: []
        DataType: 'none'
            Name: 'Artifact'
    CategoryName: 'Classification'

Detach the new label from the file.

removeLabel(myfile,reviewlabel)

Open the airframe project and create a project object.

sldemo_slproject_airframe;
proj = simulinkproject;

Get the list of files.

files = proj.Files;

Loop through each file. If a file has the extension .m, attach the label 'Utility'.

for fileIndex = 1:numel(files)
   file = files(fileIndex);
   [~, ~, fileExtension] = fileparts(file.Path);
   if strcmp(fileExtension,'.m')
       addLabel(file,'Classification','Utility');
   end
end

In the Project Files view, the Classification column displays the label Utility for each .m file in the utilities folder.

Open the airframe project and create a project object.

sldemo_slproject_airframe;
proj = simulinkproject;

Create a new category 'Review'.

createCategory(proj,'Review','char');

For the new category, create a label 'To Review'.

reviewCategory = findCategory(proj,'Review');
createLabel(reviewCategory,'To Review');

Get a particular file by name.

myfile = findFile(proj,'models/AnalogControl.slx')

myfile = 

  ProjectFile with properties:

      Path: 'C:\Work\temp\slexamples\airframe\models\AnalogControl.slx'
    Labels: [1x1 slproject.Label]
 Revision: '2'
SourceControlStatus: Unmodified

Attach the label 'To Review' and a character vector of label data to the file.

addLabel(myfile,'Review','To Review','Whole team design review')

Index into the Labels property to get the second label attached to this particular file, and see the label data.

myfile.Labels(2)

ans = 

  Label with properties:

            File: 'C:\Work\temp\slexamples\airframe\models\AnalogControl.slx'
            Data: 'Whole team design review'
        DataType: 'char'
            Name: 'To Review'
    CategoryName: 'Review'

In the Project Files view, for the AnalogControl.slx file, the Review column displays the To Review label with label data.

Alternatively, you can set or change label data using the data property.

mylabel = myfile.Labels(2);
mylabel.Data = 'Final review';