Looking at the Google results for divorce lawyers, it looks like most of them do child custody settlements as part of litigating the divorce itself, so no special credential should be required.
Divorce attorneys are meant help those seeking legal advice apply the laws to their specific situation. Although there are likely certain attorneys who are more favorable to helping men, this type of service is often not categorized by gender.
An attorney is an attorney, no matter what. That said, attorneys, like doctors, specialize in certain types of law. Distinguishing these two kinds of attorneys is like asking what the difference is between a urologist and a nephrologist. Did you know there are even specialized physicians within a certain field? Example, surgical ophthalmology vs. neuro-ophthalmology. This is also true of attorneys.
They specialize in certain goods because they have the resources to make a lot of that product.
Not exactly certain what you mean by "credentials" but if they are authorized to make arrests they will have a "comission card."
Countries specialize in producing certain goods for many reasons, but the most common is the condition of the soil and climate.
Some district attorneys include the London Distrcit Rangers and the District Clerk's Office. Both attorneys are run by the government, so you can be certain that they are available.
Every state's bar association requires attorneys to earn a certain number of CLEs each year.
A doctor can specialize in a certain field by completing residency requirements in that field. In addition, they can also complete a fellowship in another sub speciality.
Monopoly
Not so sure
Some ophthalmologists further specialize in certain areas of the eye, such as corneal or vitreo-retinal specialists.
(in the US) All attorneys are 'capable' of handling these types of cases but, that being said, most attorneys usually tend to specialize in certain areas of the law. If you are having problems with your birth identity you would probably be best served by employing an attorney in local practice in the county in which you were born and begin action to have your record corrected by someone with local knowledge.