4.8 System [2]Feature Guide 351Feature Guide References1.1.3.3 Call Waiting1.3.1.3 Do Not Disturb (DND)2.3.5 Flexible Numbering/Fixed Numbering4.8.14 Class of Service—COS Settings [2-7-1]Each extension, doorphone port, incoming call distribution group, and CO line group belongs to a certainCOS. Certain features can be programmed to behave differently depending on the COS. A maximum of 64COS can be programmed.TRS / CORestrictions to features related to making CO line calls can be programmed for each COS.COS NameSpecifies the name of the COS.DefaultNot stored.Value RangeMax. 20 charactersFeature Guide ReferencesNoneTRS Level—Day, Lunch, Break, NightSpecifies the Toll Restriction (TRS) level for making CO line calls in each time mode.Default1Value Range1: Allows all CO line calls2–6: Restricts CO line calls according to the combination of the Denied and Exception Code Tables7: Restricts all CO line callsProgramming References4.8.8 Time Service—Week Table [2-5-1]4.9.1 Trunk Group—TRG Settings [3-1-1]—Main—COS4.9.6 Incoming Call Distribution Group—Group Settings [3-5-1]—Main—COS4.10.1 Wired Extension—Extension Settings [4-1-1]—Main—COS4.10.7 Portable Station—Extension Settings [4-2-1]—Main—COS4.11.1 Doorphone [5-1]—COS