Shaykh Ibn Baz explains that when a person is truthful in his claim (as in truly following the way of the Salaf in creed and methodology), then there is no harm in such a thing, rather it is a necessary commendation.

سئل رحمه الله - : ما تقول فيمن تسمى بالسلفي والأثري ، هل هي تزكية؟ فأجاب سماحته : (إذا كان صادقاً أنه أثري أو أنه سلفي لا بأس، مثل ما كان السلف يقول: فلان سلفي، فلان أثري، تزكية لا بد منها، تزكية واجبة).( التحفة المهدية لمن سأل عن معنى السلفية ص 35) وهي من محاضرة مسجلة بعنوان: "حق المسلم"، في 16/1/1413 بالطائف.)

Allaamah, Abdul-Azeez Ibn Baz - the [former] mufti of Saudi Arabia (rahimahullaah) was asked: What do you say about the one who calls himself 'Salafi' or 'Athari'? Is this is a tazkiyah (purification) of his own self? So he replied - may Allaah have mercy upon him:

When he is being truthful [in his claim] that he is Salafi or Athari then there is not harm in that, [this is] similar to what the Salaf used to say, 'So and so is a Salafi', 'So and so is Athari'. This is a tazkiyah (commendation) which is necessary, a tazkiyah that is obligatory.

Source: Cassette: Haqq ul-Muslim 16/1/1413 Ta'if