The atlas holds these words three times, and the reason is worth explaining rather than hiding. There is a confession, catalogued here among the creeds because that is what its content is. There is a recited formula, catalogued among the mantras beside the other short Arabic phrases of daily devotion, because that is how it is used in the prayer and the call to prayer. And there is a rite, catalogued among the rituals as the act of conversion, because saying these words with intent before witnesses is how a person becomes a Muslim.
They are cross-linked so that a reader arriving at any one of them finds the others. What separates them is not the words, which are identical, but the question each answers. What does Islam confess is answered by the creed. What is said in the prayer is answered by the formula. How does someone enter Islam is answered by the rite, and only there does the presence of witnesses and the requirement of intent become part of the fact.
That the same utterance can be all three at once is a feature of the Shahada rather than an artefact of cataloguing. Few religious texts carry doctrinal, liturgical and legal force in the same breath. Its use in conversion also carries legal consequences in classical jurisprudence, which is a reminder that a creed can be an act and not only a description.