The chord symbol iii could be followed by the letter a to indicate that it is F# minor chord in root position (ie not inverted) - D major scale chord iiia. Instead, iii could be followed by the letter b to indicate that it is F# minor chord in 1st inversion - D major scale chord iiib.
According to the Centers for Disease Control and Prevention, a baby is considered an infant until he reaches one year of age. During this stage, the infant reaches several developmental milestones.
A human baby in his first year of life is referred to as an infant. However, until they complete first three months of their lives, small babies are newborns and technically they are infants between 3-12 months of age. However, there are places where human babies up to 3 years of age are referred to as infants.