KB: Control component parameter appearance in schematic

Solution Details

• To configure Comment/Designator parameters, open the schematic library document (*.SchLib) for unmanaged component or right-click to edit managed component in A365 within which open the symbol editor, and go to Tools ► Document Options... . The Library Options are now displayed in the Properties panel. Enable the Show Comment/Designator option. The component comment and designator are now displayed and their location/font can be changed.

• More generally for other parameters, the visibility is controlled by 'Visible On Add' attribute in Dblib, or similarly, for those on managed components in A365 workspace, in Explorer panel, right-click on a respective component folder, select 'Properties...', in Edit Folder popup dialog. If further control such as relative positioning is required, it can be specified in the symbol editor, Properties panel, General tab, Parameters section, Add button pulldown, select Parameter and click eye icon to have the text string shown on the desired location.

Comment/Designator

1. Open the schematic library document (*.SchLib) if unmanaged, or right-click on a managed component either in Explorer or Components panel, within which open the symbol editor

2. Tools ► Document Options...

3. The Library Options are now displayed in the Properties panel. Enable the Show Comment/Designator option.

4. The text string of Comment and Designator shown in the symbol editor can be selected and their location/font can be changed.

It is worth noting that for system-defined Comment and Designator parameters, 'Override Library Primitive' option in Preferences, Schematic » Defaults, under Primitive List section, can overule the corresponding setting you have in your library for each component.
https://www.altium.com/documentation/altium-designer/schematic-placement-editing-techniques#!comment_properties
https://www.altium.com/documentation/altium-designer/schematic-placement-editing-techniques#!designator_properties

Other parameters

Inclusive of other user-defined parameters on unmanaged components of schlib, visibility/color/font/location can be controlled in SCHLIB List panel, with panel display scope in blue text at the top set to 'Edit all objects from all components include only Parameters'.  If some custom concatenation or truncation required, a text string object can be placed manually as a part of schematic symbol in a form of special string.
If instead parameters are defined externally in dblib, its visibility is controlled by 'Visible On Add' column.
Similarly, for those on managed components, its visibility is controlled on a respective component folder basis in Explorer panel, in Edit Folder dialog accessed by right-click, Properties...:

https://www.altium.com/documentation/altium-designer/explorer-panel#!controlling-parameter-visibility-when-placing-components

On unmanaged or managed components, if further parameter control such as relative positioning is required, the text string placeholder can be specified in the symbol editor.

1. Open the schematic library document (*.SchLib) if unmanaged, or right-click on a managed component either in Explorer or Components panel, within which open the symbol editor

2. Properites panel, General tab, Parameters section, select Parameter from Add button pulldown

3. Click eye icon to have the corresponding text string shown.

4. Select the text string to modify its attribute in Properties panel

The parameter value can be anything, but it's convenient to set something to be able to position the parameter.  Don't forget to set the parameter to be visible.  You can add as many placeholder parameters as you like.  When you select the placeholder parameter in the editor then the properties will allow you to make additional settings for the Font, and for the auto positioning.

Updating parameters from source:

When updating components from libraries/workspace, setting on how parameter attributes should or should not be updated need to be cared.

• Unmanaged components from library:

https://www.altium.com/documentation/altium-designer/updating-components-footprints#!defining-default-update-actions

• Managed components in workspace:

https://www.altium.com/documentation/altium-designer/managing-content-with-item-manager#!update-options

Related open issue/request you might want to follow BC/Forum on parameter ordering:
https://bugcrunch.live.altium.com/#/bug/17639
https://forum.live.altium.com/#posts/205750/673745
https://bugcrunch.live.altium.com/#/idea/4543 (on multi-part)