why need to check if inline doc is already defined?

*To*: mathgroup at smc.vnet.net*Subject*: [mg115583] why need to check if inline doc is already defined?*From*: Xah Lee <xahlee at gmail.com>*Date*: Sat, 15 Jan 2011 04:46:25 -0500 (EST)

i noticed that in many addon packages, they define the inline doc by first checking whether it is already defined, e.g. at ... Mathematica/7.0/AddOns/Packages/FourierSeries/ FourierSeries.m like this: If[Not@ValueQ[SomeF::usage],SomeF::usage = "..." why does it need to check if it is already defined? Xah =E2=88=91 http://xahlee.org/