I have been using trimmomatic for quite some time, but realized that I don't get something. So one can use LEADING and TRAILING options to remove bases from the beginning and end of the read, respectively. From manual: LEADING Remove low quality bases from the beginning. As long as a base has a value below this threshold the base is removed and the next base will be investigated.
My question is: "From the beginning" means from the beginning until the end of the read? If yes, then what is the meaning of having TRAILING option if the whole read is scanned? Otherwise, until which base does trimmomatic scan by LEADING option?