Name starting with number can be set, but can't be unset.

[William Park]

Configuration Information [Automatically generated, do not change]:
Machine: i686
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i686' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i686-pc-linux-gnu' 
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/local/share/locale' -DPACKAGE='bash' 
-DSHELL -DHAVE_CONFIG_H  -I.  -I. -I./include -I./lib   -O4 -march=i686
uname output: Linux node1 2.6.7 #6 SMP Sun Aug 22 23:49:58 EDT 2004 i686 
unknown unknown GNU/Linux
Machine Type: i686-pc-linux-gnu

Bash Version: 3.0
Patch Level: 0

Description:

    Shell variable can start with number and can even be printed with
    'declare', as in
        1=aaa
        1a=bbb
        declare -p 1 1a

    But, they can't be removed, as in
        unset 1 1a              --> ...: not a valid identifier

    Bash-2.05b correctly gives me error, however.