When it comes to using the phrase "doubtfully called," there are a variety of synonyms that can convey a similar meaning. One such synonym is "questionably labeled," which suggests uncertainty or ambiguity about the accuracy of the label. Another option is "tentatively named," which implies a lack of certainty or a need for further verification. "Dubiously called" is another possible synonym, which emphasizes a sense of skepticism or suspicion. Ultimately, the choice of synonym will depend on the context and tone of the situation, but these options offer a few possible alternatives to the phrase "doubtfully called".