What subjects do the call letters cover?
Subclass B Philosophy (General).
Subclass BC Logic.
Subclass BD Speculative philosophy.
Subclass BF Psychology.
Subclass BH Aesthetics.
Subclass BJ Ethics.
Subclass BL Religions. Mythology. Rationalism.
Subclass BM Judaism.
Subclass BP Islam. Bahai Faith. Theosophy, etc.
Subclass BQ Buddhism.
Subclass BR Christianity.
Subclass BT Doctrinal Theology.
Subclass BV Practical Theology.
Subclass BX Christian Denominations.