Modifier is a simple extension that allows you to define rules for automatic replacement and other modification of PDUs.

## Modify rule

For each modification you have to create rule:

- Name: for clarity.
- Description: for clarity.
- Enabled
- Tag:
  - "": Rule will be applied to any PDU.
  - "some_tag": Rule will be applied only to PDUs with specified tag.
- Rest of the configuration depends on the modifier module.
- Occurrence:
  - -1: All occurrences will be replaced.
  - >= 0: Only specified occurrence (starting from 0), will be replaced (0., 1., 2., ...).
- What: what should be replaced.
- With: [What] will be replaced with [With].

## Modify rule group

Modify rule groups contain modify rules. These groups can be then bound with particular modifier interceptors.

It is possible to bind one rule group to multiple interceptors, so it is up to you, if you will create just one group or multiple groups.

## Modifier interceptor

In order to setup automatic modification, you have to create modifier interceptors in one or both directions and you have to specify, which rule group should these interceptors use.

## Internal modifiers

### Replace

Replace is a simple modifier that allows you to setup automatic replacement rules.

- Occurrence:
  - -1: All occurrences will be replaced.
  - >= 0: Only specified occurrence (starting from 0), will be replaced (0., 1., 2., ...).
- What: what should be replaced.
- With: [What] will be replaced with [With].

## Special tags

In order to specify, which PDUs should be processed by modify rules, you can tag them using the following tags (all PDUs are processed by default):

- no_modifier - tagged PDU won't be processed by modification rules,
- modifier - tagged PDU will be processed by modification rules even if it already has no_modifier tag.