What is deprecated?

Some articles on deprecated:

Geobox - Other Guidelines
... The use of this template for mountains is deprecated ... The use of this template for mountain ranges is deprecated ... The use of this template for provinces is deprecated ...
HTML Element - Historic Elements
... of the early HTML developed by Tim Berners-Lee from 1989–91 they are mentioned in HTML Tags, but deprecated in HTML 2.0 and were never part of HTML standards ... These existed in HTML Tags deprecated in HTML 2.0 invalid in HTML 4.0 ... nextid existed in HTML Tags (described as obsolete) deprecated in HTML 2.0 invalid in HTML 3.2 and later ...
Troland - Conversions To Other Units
3.142 La (lamberts) (unit officially deprecated) 2919 footlamberts (unit officially deprecated) 2919 equivalent foot-candles (unit officially deprecated) 31416 blondels (unit ...
Cite Map - Parameters - Deprecated
... These parameters are deprecated and will no longer work ... place the page in CategoryPages containing cite templates with deprecated parameters ...
C++11 - Features Removed or Deprecated
... dynamic exception specifications are deprecated ... keyword (useful for optimization) stdauto_ptr is deprecated ... and adapters to pointers to members, binder classes these are all deprecated ...