### 4.3 Editing symbol version attribute

Symbol version is defined using the ‘`symversion`’ attribute. The attribute value should contain two components in order tools to process it correctly: major and minor. So it looks like `major.minor`, for example, `1.2`. It is important to follow to several simple rules when you are about to edit a symbol and its version. Otherwise, the tools won’t be able to warn you on significant changes. You should remember that major changes are those that may break existing schematics and/or netlists:

- Addition or removal of pins.
- Changing position of connectable ends of pins.
- Changes in position of graphics or attributes that lead to moving pins to other position after translation.
- Change of pin attributes that may affect netlist creation.

If you did any of the above changes, please increment the major version number, especially, if your symbol is shared with other users.

The minor symbol changes are any other that do not break anything. Those are any changes in graphical stuff such as attribute placement, new lines in the body rectangle, colors etc. which do not affect the points mentioned above. Changing of any internal symbol attribute won’t break your existing schematic, so it is considered minor as well. On such changes, please increment the minor symbol version.

If the symbol you edit does not have the ‘`symversion`’ attribute, please add it. Otherwise, Lepton tools won’t be able to warn you about any changes, even breaking.