   What "threshold" means in Lempel-Ziv algorithm?
  I've google'd for this stuff and already found some info. But, I want to ensure that my interpretation is right. To my understanding,  the threshold word used by LZH or other dictionary compression algorithm explanation/specification means the minimum number of match-length in bytes, i.e. the minimum number of  bytes that match within the dictionary and the bytes in the current look-ahead buffer that have to be "surpassed" to carry-out the "encoding". So, if the match-length is less than the threshold, the phrase in the look-ahead buffer won't be encoded, but will stay as literal in the compression result. Is this correct? There must be some compression guru around here to help me ;)PS: sorry for the bad english   
  Usually this is correct. The threshold is the minimum match-length and every phrase of below this length stays a literal. 