These define various default site preferences, including [[PmWiki/access keys]] and component sizes.

  [=
  # Access keys - hold Alt (Windows) or Control (Mac) and 
  # tap the indicated key on your keyboard to trigger the 
  # corresponding action.
  'ak_edit'          => 'e',     # edit page
  'ak_history'       => 'h',     # page history
  'ak_recentchanges' => 'c',     # Recent Changes
  'ak_save'          => 's',     # save page
  'ak_saveedit'      => 'u',     # save and keep editing
  'ak_preview'       => 'p',     # preview page
  'ak_em'            => 'i',     # emphasized text (italic)
  'ak_strong'        => 'b',     # strong text (bold)

  # Editing components
  'e_rows' => '20',              # rows in edit textarea
  'e_cols' => '70',              # columns in edit textarea
  'Site.EditForm' => 'Site.EditForm' # location of EditForm
  =]

If you'd like to customize these preferences, to create personal user (browser) preferences, make a copy of this page somewhere, preferably as @@Profiles.''%green%insert_your_name_here%%''-Preferences@@, edit that page with your new preferred settings,
and then select [[{$FullName}?setprefs={$FullName} | Set Preferences of this Page]] on the page containing your newly created settings. 
This sets a cookie on your browser which tells PmWiki where to find your personal preference settings.

To unset this cookie and revert to PmWiki's default preferences,
select [[{$Name}?setprefs=| Revert to PmWiki Default Preferences]].

See also [[Cookbook:UserConfigurations]] about how to customise the edit form for personal use.