  A study and classification of super-short structures (SSSs) recorded during
metric type IV bursts is presented. The most important property of SSSs is
their duration, at half power ranging from 4-50 ms, what is up to 10 times
shorter than spikes at corresponding frequencies. The solar origin of the SSSs
is confirmed by one-to-one correspondence between spectral recordings of
Artemis-IV1 and high time resolution single frequency measurements of the
TSRS2. We have divided the SSSs in the following categories:
  1. Broad-Band SSSs: They were partitioned in two subcategories, the
SSS-Pulses and Drifting SSSs;
  2. Narrow-band: They appear either as Spike-Like SSSs or as Patch-Like SSSs;
  3. Complex SSS: They consist of the absorption-emission segments and were
morphologically subdivided into Rain-drop Bursts (narrow-band emission head and
a broad-band absorption tail) and Blinkers.
