Constraints

What is the advantage to the CONSTRAINT clause vs constraints in the 
table/field definition?  For example:

CREATE TABLE "Phone Number" (
"Phone ID" INTEGER GENERATED BY DEFAULT AS IDENTITY(START WITH 0) NOT NULL
PRIMARY KEY,
"Patient ID" INTEGER NOT NULL,
"Number" VARCHAR(10),
"Description" VARCHAR(10),
CONSTRAINT FK_PAT_PHN FOREIGN KEY ("Patient ID") REFERENCES "Patient" ("ID
Number")
);

Seems to add no real functionality, but who knows.

Dave