Roni Con - Linear and Reed-Solomon Codes Correcting Insertions and Deletions
An important model that has been considered ever since Shannon's work is that of synchronization errors. These are errors that affect the length of the received word.
The most common model for studying synchronization errors is the insertion-deletion model (insdel for short): an insertion error is when a new symbol is inserted between two symbols of the transmitted word. A deletion is when a symbol is removed from the transmitted word.