type ShortString = string;
typedef SmallString<255> ShortString; //
Represents a string whose maximum length is 255 characters.
A ShortString is 0 to 255 single-byte characters long. While the length of a ShortString can change dynamically, its memory is a statically allocated 256 bytes; the first byte stores the length of the string, and the remaining 255 bytes are available for characters. If S is a ShortString variable, Ord(S), like Length(S), returns the length of S; assigning a value to S, like calling SetLength, changes the length of S. ShortString is maintained for backward compatibility only.
The Delphi language supports short-string types--in effect, subtypes of ShortString--whose maximum length is anywhere from 0 through 255 characters. These are denoted by a bracketed numeral appended to the reserved word string.
When you assign a value to a ShortString variable, the string is truncated if it exceeds the maximum length for the type.