def return_markers(self):
        """Reads the notes of the Ktlx recordings.
        """
        ent_file = self._filename.with_suffix('.ent')
        if not ent_file.exists():
            ent_file = self._filename.with_suffix('.ent.old')

        try:
            ent_notes = _read_ent(ent_file)

        except (FileNotFoundError, PermissionError):
            markers = []

        else:
            allnote = []
            for n in ent_notes:
                try:
                    n['value'].keys()
                    allnote.append(n['value'])
                except AttributeError:
                    lg.debug('Note of length {} was not '
                             'converted to dict'.format(n['length']))

            s_freq = self._hdr['erd']['sample_freq']
            pcname = '0CFEBE72-DA20-4b3a-A8AC-CDD41BFE2F0D'
            note_time = []
            note_name = []
            note_note = []
            for n in allnote:
                if n['Text'] == 'Analyzed Data Note':
                    continue
                if not n['Text']:
                    continue
                if 'User' not in n['Data'].keys():
                    continue
                user1 = n['Data']['User'] == 'Persyst'
                user2 = False  # n['Data']['User'] == 'eeg'
                user3 = n['Data']['User'] == pcname
                user4 = n['Data']['User'] == 'XLSpike - Intracranial'
                user5 = n['Data']['User'] == 'XLEvent - Intracranial'
                if user1 or user2 or user3 or user4 or user5:
                    continue
                if len(n['Data']['User']) == 0:
                    note_name.append('-unknown-')
                else:
                    note_name.append(n['Data']['User'].split()[0])
                note_time.append(n['Stamp'] / s_freq)
                note_note.append(n['Text'])

            markers = []
            for time, name, note in zip(note_time, note_name, note_note):
                m = {'name': note + ' (' + name + ')',
                     'start': time,
                     'end': time,
                     'chan': None,
                     }
                markers.append(m)

        return markers
Reads the notes of the Ktlx recordings.