[[step]]
    action = "ExtractRegions"
    regions = [
        {segment= "Read1", start = 0, length = 8},
        {segment= "Read1", start = 12, length = 4},
    ]
    label = "umi"
    region_separator = "_" # (optional) str, what to put between the regions, defaults to '_'

[[step]]
    action = "StoreTagInComment" 
    label = "umi"

Extract a sequence from the read and place it in the read name’s comment section, so a (space separated) ‘key=value’ pair is added to the read name.

Supports multiple region-extraction.

See the tag section for more tag generation options.

(there used to be an ExtractToName step before we introduced tag based analysis, hence this piece of how-to documentation in the reference section)