A question arises here: i.e., "Are there proper names which cannot be reformulated in the form of definite descriptions?" According to Russell, there are two types of proper names. They are:

1. Ordinary proper name
2. Logically proper name

In the case of ordinary proper names it does not matter whether a proper name is denoting or not. But in the case of a logically proper name, it must designate something as 'single', 'one' and 'simple'. It can be replaced by descriptions. It can thus be conveyed through definite descriptions. All the descriptions are embedded in the knowledge of acquaintance.

In the case of logically proper names, something is designated as 'symbol'. For example, "This is white". In this sentence the word 'this' is a logically proper name which stands for an object. It is because it does not forecast any attribute. Thus, we obtain the referent of the proper name and consider this sentence is meaningful and thereby significant.