syntax的语法问题

qtdszws

ldap system administration中的一句话

The SYNTAX keyword specifies the object identifier (OID) of the encoding rules used for storing and transmitting values of the attribute type. The number enclosed by curly braces ({ }) specifies the minimum recommended maximum length of the attribute's value that a server should support.

又是最小又是最大，看不懂，哪位帮忙解释一下？