CAD tip # 6433:

Using FLay you can put all newly created Texts, Dimensions, Hatches etc. to the respective predefined layers. If the layer does not exist, it will be created.

Just load the Flay.vlx file (APPLOAD) and start the FLAY command to load the definitions and enable the reactor.

The free CS FLay utility can be downloaded from Download or from Autodesk Apps.

Since version 2.1 you can autoswitch also layers for LISP commands (like TCIRCLE). But you will need to enable it first by setting:
(setq FL:LISPREACTOR T)

Another LISP variable can keep the switched layer set - see:
(setq FL:STAYSWITCHED T)

Since version 2.2 you can invoke the FLAYSUP1 command to disable FLAY reaction just for the next 1 command (which would fire layer-switch reaction otherwise).

Since version 2.3 you can also preset specific blocks (block names) to specific layers.

Format of the FLAY.TAB
The FLAY.TAB is a text file. The layers are defined on lines starting with an asterisk ("*"). The next line defines the list of all drawing commands or blocks which will be automatically redirected to this layer:

* layer_name [layer_color]
command1 command2 command3 @blockname1 @blockname2...

where:
layer_name - the name of the layer to be used
layer_color - (optional) color to be used for the newly created layer
command1 command2 - English command names to be redirected to that layer
@blockname - names (wcmatch masks) of blocks which will be inserted in that layer

Example:
* MYTEXTS
TEXT DTEXT MTEXT TCIRCLE @AnnotLabel*
* ROUND_THINGS
ARC CIRCLE ELLIPSE SPLINE