This paper presents two concise novel steganographic schemes of strings comparing and formats converting based on the Row-Major Mapping Relation (RMMR). In general, the number of concealed secret bits( m) is far smaller than that of available host bits(n). Based on the property, we proved that if n \underline{\underline > } 2^m -1, the alteration rates of our proposed schemes are independent of n, and the alteration rates are close to m-1 when m is large. Even in the worst case that the amount of the secret bits is equal to that of the host bits and over half of the host bits are altered, our proposed scheme based on the Row-Major Mapping Relation with complement (RMMRwC) can decrease the alteration rate. From practical analyses and theoretical inductions, all results show that our novel schemes have advantages over steganography.