10. An apparatus comprising: a processor; memory including computer program code; the memory and the computer program code configured to, with the processor, cause the apparatus to: receive a handwritten input character string having an unrecognized character; determine at least one character sub-string preceding the unrecognized character in the input character string; provide, by means of handwriting recognition, one or more candidate characters for the unrecognized character; identify, amongst stored character strings, one or more character strings comprising an initial character sub-string identical to the determined character sub-string; and select, based on the identified one or more character strings, one of the one or more candidate characters that is most likely to be a correct recognition of the unrecognized character, wherein if a complete character string preceding the unrecognized character in the input character string is not identical to any stored character string or an initial sub-string of any stored character string, the apparatus is caused to determine at least one character sub-string by: identifying any initial character sub-string of the input character string preceding the unrecognized character, which is identical to one of the stored character strings or to an initial character sub-string of one or more of the stored character strings, and which together with a succeeding character is not identical to any one of the stored character strings or to an initial character sub-string of any one of the stored character strings; and determining a character sub-string consisting of a terminal character sub-string of the input character string preceding the unrecognized character and succeeding any identified initial character sub-string; else the apparatus is caused to determine at least one character sub-string by: determining a character sub-string consisting of said complete character string preceding the unrecognized character in the input character string.
10. An apparatus comprising: a processor; memory including computer program code; the memory and the computer program code configured to, with the processor, cause the apparatus to: receive a handwritten input character string having an unrecognized character; determine at least one character sub-string preceding the unrecognized character in the input character string; provide, by means of handwriting recognition, one or more candidate characters for the unrecognized character; identify, amongst stored character strings, one or more character strings comprising an initial character sub-string identical to the determined character sub-string; and select, based on the identified one or more character strings, one of the one or more candidate characters that is most likely to be a correct recognition of the unrecognized character, wherein if a complete character string preceding the unrecognized character in the input character string is not identical to any stored character string or an initial sub-string of any stored character string, the apparatus is caused to determine at least one character sub-string by: identifying any initial character sub-string of the input character string preceding the unrecognized character, which is identical to one of the stored character strings or to an initial character sub-string of one or more of the stored character strings, and which together with a succeeding character is not identical to any one of the stored character strings or to an initial character sub-string of any one of the stored character strings; and determining a character sub-string consisting of a terminal character sub-string of the input character string preceding the unrecognized character and succeeding any identified initial character sub-string; else the apparatus is caused to determine at least one character sub-string by: determining a character sub-string consisting of said complete character string preceding the unrecognized character in the input character string. 14. The apparatus of claim 10 , wherein the stored character strings are chosen from the following type of character strings: phrases, words, word stubs and frequently used character sequences.