: The four pillars, the one central core, and the two secondary gates.
: Sometimes, such a string could simply be a note or a piece of information jotted down. For example, a user might make a note about a product: waaa412 av new
:
# Substring features features['has_waaa'] = 'waaa' in identifier features['has_412'] = '412' in identifier features['is_av_edition'] = 'av' in identifier features['is_new_version'] = 'new' in identifier : The four pillars, the one central core,